Psma targeted radiohalogenated urea-polyaminocarboxylates for cancer radiotherapy

ABSTRACT

Small molecule radiohalogenated PSMA inhibitors and metal complexes thereof and their use in radioimaging and radiotherapy for treating PSMA-related diseases, including prostate cancer, are disclosed. The combination of small molecule radiohalogenated PSMA inhibitors with a competitive PSMA ligand for reducing off target accumulation of the radiohalogenated PSMA inhibitor also is disclosed.

BACKGROUND

Prostate cancer is the leading cancer in the U.S. population and thesecond leading cause of cancer death in men. Therapy for locallyadvanced disease remains contentious and an increasing number ofdisparate options are available. High-sensitivity, low molecular weightimaging agents for prostate cancer using the prostate-specific membraneantigen (PSMA) as a target are currently under development. PSMA is amarker for androgen-independent disease that also is expressed on solid(nonprostate) tumor neovasculature. PSMA-based imaging agents are knownin the art, however, PSMA-based radiotherapy agents can exhibitundesirable off-target effects, such as renal toxicity and dry mouth.

SUMMARY

In some aspects, the presently disclosed subject matter provides acompound of formula (I):

wherein: Z is tetrazole or CO₂Q; Q is H or a protecting group; m is aninteger selected from the group consisting of 1, 2, 3, 4, and 5; R isindependently H or —CH₂—R¹; wherein R¹ is:

wherein X₁ is —CR³, —C—X, or N, wherein R³ is H or C₁-C₄ alkyl; whereinX is selected from the group consisting of a radioisotope of iodine, aradioisotope of bromine, and a radioisotope of astatine; or X is halogenwhen at least one L is a substituted arylene; L is a linker selectedfrom the group consisting of C₁, C₂, C₃, C₄, C₅, and C₆ alkylene, C₃,C₄, C₅, and C₆ cycloalkylene, and arylene, each of which can besubstituted to unsubstituted; W is selected from the group consisting of—NR²—(C═O)—, —NR²—(C═S)—, —(C═O)—NR²—, and —(C═S)—NR²—; wherein eachoccurrence of L and W can be the same or different; R² is H or C₁-C₄alkyl; n is an integer selected from the group consisting of 1, 2, and3; Ch is a chelating agent that can comprise a metal; andpharmaceutically acceptable salts thereof.

In particular aspects, X is selected from the group consisting of ¹²⁵I,¹²³I, ¹³¹I, ¹²⁴I, ²¹¹At, ⁷⁷Br, and ^(80m)Br. In yet more particularaspects, X is ¹²⁵I or ²¹¹At. In certain aspects, when at least one L issubstituted arylene, X is halogen.

In even yet more particular aspects, the chelating agent is selectedfrom the group consisting of:

In certain aspects, the metal chelating agent comprises a metal selectedfrom the group consisting of: Y, Lu, Tc, Zr, In, Sm, Re, Cu, Pb, Ac, Bi,Al, Ga, Re, Ho and Sc. In more certain aspects, the metal is ¹⁷⁵Lu.

In particular aspects, the compound of formula (I) has the followingformula:

wherein L is selected from C₁, C₂, C₃, C₄, C₅, and C₆ alkylene; whereinX₁ is —CR³, —C—X, or N, wherein R³ is H or C₁-C₄ alkyl; and wherein X isselected from the group consisting of a radioisotope of iodine, aradioisotope of bromine, and a radioisotope of astatine.

In more particular aspects, the compound of claim 1, wherein thecompound of formula (I) has the following formula:

wherein: p is an integer selected from the group consisting of 1, 2, 3,4, 5, and 6; and X is halogen; X₁ is —CR³, —C—X, or N, wherein R³ is Hor C₁-C₄ alkyl; and X₂ is selected from the group consisting of aradioisotope of iodine, a radioisotope of bromine, and a radioisotope ofastatine; and wherein M⁺ is a metal, which can be present or absent. Incertain aspects, M⁺ is a metal selected from the group consisting of: Y,Lu, Tc, Zr, In, Sm, Re, Cu, Pb, Ac, Bi, Al, Ga, Re, Ho and Sc, andradioisotopes thereof.

In yet more particular aspects, the compound of formula (I) is selectedfrom the group consisting of:

wherein X is ¹²⁵I or ²¹¹At.

In other aspects, the presently disclosed subject matter provides amethod for treating one or more PSMA expressing tumors or cells, themethod comprising contacting the one or more PSMA expressing tumors orcells with an effective amount of a compound of formula (I).

In certain aspects, the one or more PSMA-expressing tumor or cell isselected from the group consisting of: a prostate tumor or cell, ametastasized prostate tumor or cell, a lung tumor or cell, a renal tumoror cell, a glioblastoma, a pancreatic tumor or cell, a bladder tumor orcell, a sarcoma, a melanoma, a breast tumor or cell, a colon tumor orcell, a germ cell, a pheochromocytoma, an esophageal tumor or cell, astomach tumor or cell, and combinations thereof.

In particular aspects, the method further comprises administering ablocking agent in combination with the compound of formula (I), whereinthe blocking agent reduces accumulation of the compound of formula (I)in one or more PSMA expressing cells in an off-target organ. In yet moreparticular aspects, the off-target organ is selected from the groupconsisting of blood, stomach, spleen, thyroid gland, salivary gland,lacrimal gland, and kidney.

In certain aspects, the blocking agent comprises a PSMA-based blockingagent. In more certain aspects, the PSMA-based blocking agent is acompound of formula (I) in which the compound is not radiohalogenated,wherein the compound of formula (I) used as a blocking agent and thecompound of formula (I) used as a therapeutic agent can be the same ordifferent.

In some aspects, the presently disclosed subject matter provides amethod for imaging one or more prostate-specific membrane antigen (PSMA)tumors or cells, the method comprising contacting the one or more tumorsor cells with an effective amount of a compound of formula (I) andmaking an image, wherein X of the compound of formula (I) is ¹²⁴I andthe imaging comprises positron emission tomography (PET).

In yet other aspects, the presently disclosed subject matter provides aone-pot, multi-step synthesis method for preparing a radiotherapeuticcompound of formula (Ia):

wherein X is a radiohalide, the method comprising:

(a) providing a precursor compound of formula (Ia′):

(b) contacting the precursor compound of formula (Ia′) with solutioncomprising a radiohalide and N-chlorosuccinimide, followed by theaddition of glacial acetic acid to form a radiohalogenated precursorcompound of formula (Ia″):

(c) contacting the radiohalogenated precursor compound of formula (Ia″)with trifluoroacetic acid to form a radiohalogenated compound of formula(Ia′″):

(d) contacting the radiohalogenated compound of formula (Ia′″) withNaOAc and Lu(NO₃)₃ to form a radiotherapeutic compound of formula (Ia).

In yet other aspects, the presently disclosed subject matter provides apharmaceutical composition comprising a compound of formula (I) and apharmaceutically acceptable carrier.

In even yet other aspects, the presently disclosed subject matterprovides a kit for treating one or more PSMA expressing tumors or cells,the kit comprising a compound of formula (I). In particular aspects, thekit further comprises a blocking agent.

Certain aspects of the presently disclosed subject matter having beenstated hereinabove, which are addressed in whole or in part by thepresently disclosed subject matter, other aspects will become evident asthe description proceeds when taken in connection with the accompanyingExamples and Figures as best described herein below.

BRIEF DESCRIPTION OF THE FIGURES

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawings will be provided by the Office upon request and paymentof the necessary fee.

Having thus described the presently disclosed subject matter in generalterms, reference will now be made to the accompanying Figures, which arenot necessarily drawn to scale, and wherein:

FIG. 1A, FIG. 1B, FIG. 1C, FIG. 1D, FIG. 1E, and FIG. 1F show thebiodistribution (% ID/g) of [¹²⁵I]2 and [¹²⁵I/²¹¹At]3 with and withoutblocker (DClBzL(YC-1-27));

FIG. 1G is a chemical structure of [¹²⁵I]2;

FIG. 1H is a chemical structure of [¹²¹I/²¹¹At]3;

FIG. 2 shows [²¹¹At]VK0290-Lu Treatment (3.7 MBq, 100 uCi) in athymicmice bearing both PSMA+ (PiP) and PSMA− (flu) tumor xenografts. Fivemice were treated; and

FIG. 3A and FIG. 3B demonstrate that [²¹¹At]VK-02-90-Lu exhibiteddose-dependent efficacy. FIG. 3A is a SC model of PSMA+ PC3-PIP andPSMA− PC3-flu model. The tumor volume increase of more than 4-fold wasscored as death of animals. FIG. 3B is a metastatic model of PSMA+PC3ML/PSMA/fLuc.

DETAILED DESCRIPTION

The presently disclosed subject matter now will be described more fullyhereinafter with reference to the accompanying Figures, in which some,but not all embodiments of the presently disclosed subject matter areshown. Like numbers refer to like elements throughout. The presentlydisclosed subject matter may be embodied in many different forms andshould not be construed as limited to the embodiments set forth herein;rather, these embodiments are provided so that this disclosure willsatisfy applicable legal requirements. Indeed, many modifications andother embodiments of the presently disclosed subject matter set forthherein will come to mind to one skilled in the art to which thepresently disclosed subject matter pertains having the benefit of theteachings presented in the foregoing descriptions. Therefore, it is tobe understood that the presently disclosed subject matter is not to belimited to the specific embodiments disclosed and that modifications andother embodiments are intended to be included within the scope of theappended claims.

I. PSMA Targeted Radiohalogenated Ureas for Cancer Radiotherapy

A variety of high affinity radiohalogenated, urea-based PSMA inhibitorsthat selectively image prostate tumors in experimental models have beendeveloped. Because of the favorable pharmacokinetic profile of thisclass of compounds, i.e., low nonspecific binding, lack of metabolism invivo and reasonable tumor residence times, it was thought that thestrategy adopted for molecular imaging could be extended to molecularradiotherapy. This approach is analogous to that of radioimmunotherapy(RIT), which has proved remarkably successful in the treatment oflymphoma with two commercial products routinely integrated into clinicalpractice. RIT, however, is fraught with similar difficulties to the useof radiolabeled antibodies for imaging, including prolonged circulationtimes, unpredictable biological effects, and the occasional need forpre-targeting strategies. Furthermore, antibodies may have less accessto tumors than low molecular weight agents, which can be manipulatedpharmacologically.

The development of low molecular weight radiotherapeutic agents,however, is much different than developing radiopharmaceuticals forimaging in that longer tumor residence times, as well as shorternon-target organ residence times, are desired for radiotherapeuticagents. Radiotherapeutic halogens include Auger electron emittingradionuclides ¹²⁵I, ¹²³I and ^(80m)Br, beta-particle emitters ¹³¹I, and⁷⁷Br, and alpha-particle emitter ²¹¹At. 1-124 is a positron emitter and1-124 labeled agents would permit PET imaging and individual dosimetryin patients prior to radiotherapy with the corresponding agent labeledwith the radiotherapeutic nuclide. Astatine-211 has attractiveproperties for radiopharmaceutical therapy, including a 7.2-hr half-lifeand 100% α-particle emission per decay. Astatine-211 also lacksα-particle emitting daughters that can escape from the targetingmolecule, which can lead to excessive radiation dose to normal organs.Initial experiments in mice using I-125/I-131/ and At-211 labeled ureasdemonstrated high specific PSMA positive tumor uptake, but suffered fromslow renal clearance, which can lead to renal toxicity. InternationalPCT Patent Application Publication No. WO2017070482 A2, to Pomper etal., published Apr. 27, 2017, which is incorporated herein by referencein its entirety. In addition, At-211 labeled ureas had significantaccumulation in the stomach, which is symptomatic of free At-211.

Radiometal complexed DOTA-urea conjugates also demonstrate high specificPSMA positive tumor uptake, but exhibit rapid renal excretion. SeeInternational PCT Patent Application Publication No. WO2017165473 A1, toPomper et al., published Sep. 28, 2017, which is incorporated herein byreference in its entirety. The presently disclosed subject matterprovides the preparation and biodistribution in mice of radioiodinatedand radioastatinated DOTA-urea conjugates with and without complexednon-radioactive metal ion.

Accordingly, in some embodiments, the presently disclosed subject matterprovides radiolabeling of a DOTA-urea with radioiodine and/or At-211using a novel tributyltin precursor followed by complexation ofnonradioactive lutetium. The radiochemistry has been reduced to amulti-step one pot synthesis with only a single HPLC purification of thefinal product. The entire process is simple enough for automation forroutine production. The chemical reactivity of At-211 decreases withtime, presumably due to a change in chemical state from radiolysis. Theradiolabeling with At-211, which has been allowed to stand 18 hours tosimulate the transport of radionuclide from site of production to siteof radiotracer synthesis also was successful, such that the presentlydisclosed chemistry is feasible using At-211 produced at a remote site.

A. Compounds of Formula (I)

In some embodiments, the presently disclosed subject matter provides acompound of formula (I):

wherein: Z is tetrazole or CO₂Q; Q is H or a protecting group; m is aninteger selected from the group consisting of 1, 2, 3, 4, and 5; R isindependently H or —CH₂—R¹; wherein R¹ is:

wherein X₁ is —CR³, —C—X, or N, wherein R³ is H or C₁-C₄ alkyl; whereinX is selected from the group consisting of a radioisotope of iodine, aradioisotope of bromine, and a radioisotope of astatine; or X is halogenwhen at least one L is a substituted arylene; L is a linker selectedfrom the group consisting of C₁, C₂, C₃, C₄, C₅, and C₆ alkylene, C₃,C₄, C₅, and C₆ cycloalkylene, and arylene, each of which can besubstituted to unsubstituted; W is selected from the group consisting of—NR²—(C═O)—, —NR²—(C═S)—, —(C═O)—NR²—, and —(C═S)—NR²—; wherein eachoccurrence of L and W can be the same or different; R² is H or C₁-C₄alkyl; n is an integer selected from the group consisting of 1, 2, and3; Ch is a chelating agent that can comprise a metal; andpharmaceutically acceptable salts thereof.

In particular embodiments, R¹ is selected from the group consisting of:

In yet more particular embodiments, X is selected from the groupconsisting of ¹²⁵I, ¹²⁴I, ¹²³I, ¹³¹I, ²¹¹At, ⁷⁷Br, and ^(80m)Br. Incertain embodiments, at least one L is substituted arylene and X ishalogen.

In even yet more particular embodiments, the chelating agent is selectedfrom the group consisting of:

In certain embodiments, the metal chelating agent comprises a metalselected from the group consisting of: Y, Lu, Tc, Zr, In, Sm, Re, Cu,Pb, Ac, Bi, Al, Ga, Re, Ho and Sc, and radioisotopes thereof. In morecertain embodiments, the metal is ¹⁷⁵Lu.

In particular embodiments, the compound of formula (I) is selected fromthe group consisting of:

In more particular embodiments, X is ¹²⁵I or ²¹¹At.

In some embodiments, the compound of formula (I) has the followingformula:

wherein: Z is tetrazole or CO₂Q; Q is H or a protecting group; m is aninteger selected from the group consisting of 1, 2, 3, 4, and 5; R isindependently H or —CH₂—R¹; R¹ is selected from the group consisting of:

wherein X is selected from the group consisting of a radioisotope ofiodine, a radioisotope of bromine, and a radioisotope of astatine; L isa linker selected from the group consisting of C₁-C₆ alkylene, includingC₁, C₂, C₃, C₄, C₅, and C₆ alkylene, C₃-C₆ cycloalkylene, including C₃,C₄, C₅, and C₆ cycloalkylene, and arylene; W is selected from the groupconsisting of —NR²—(C═O)—, —NR²—(C═S)—, —(C═O)—NR²—, and —(C═S)—NR²—;wherein each occurrence of L and W can be the same or different; R² is Hor a C₁-C₄ alkyl, including C₁, C₂, C₃, and C₄ alkyl; n is an integerselected from the group consisting of 1, 2, and 3; Ch is a chelatingagent that can comprise a metal; and pharmaceutically acceptable saltsthereof.

In particular embodiments, the compound of formula (I) has the followingformula:

wherein L is selected from C₁, C₂, C₃, C₄, C₅, and C₆ alkylene; whereinX₁ is —CR³, —C—X, or N, wherein R³ is H or C₁-C₄ alkyl; and wherein X isselected from the group consisting of a radioisotope of iodine, aradioisotope of bromine, and a radioisotope of astatine.

In more particular embodiments, the compound of formula (I) is:

wherein X is ¹²⁵I or ²¹¹At.

In other embodiments, the compound of formula (I) has the followingformula:

wherein: p is an integer selected from the group consisting of 1, 2, 3,4, 5, and 6; and X is halogen; X₁ is —CR³, —C—X, or N, wherein R³ is Hor C₁-C₄ alkyl; and X₂ is selected from the group consisting of aradioisotope of iodine, a radioisotope of bromine, and a radioisotope ofastatine; and wherein M⁺ is a metal, which can be present or absent. Inparticular embodiments, M⁺ is a metal selected from the group consistingof: Y, Lu, Tc, Zr, In, Sm, Re, Cu, Pb, Ac, Bi, Al, Ga, Re, Ho and Sc,and radioisotopes thereof.

In certain embodiments, the compound of formula (I) is selected from thegroup consisting of:

B. Methods of Treating PSMA Expressing Tumors or Cells

In some embodiments, the presently disclosed subject matter provides amethod for treating one or more PSMA expressing tumors or cells, themethod comprising contacting the one or more PSMA expressing tumors orcells with an effective amount of a compound of formula (I), thecompound of formula (I) comprising:

wherein: Z is tetrazole or CO₂Q; Q is H or a protecting group; m is aninteger selected from the group consisting of 1, 2, 3, 4, and 5; R isindependently H or —CH₂—R¹; wherein R¹ is:

wherein X₁ is —CR³, —C—X, or N, wherein R³ is H or C₁-C₄ alkyl; whereinX is selected from the group consisting of a radioisotope of iodine, aradioisotope of bromine, and a radioisotope of astatine; or X is halogenwhen at least one L is a substituted arylene; L is a linker selectedfrom the group consisting of C₁, C₂, C₃, C₄, C₅, and C₆ alkylene, C₃,C₄, C₅, and C₆ cycloalkylene, and arylene, each of which can besubstituted to unsubstituted; W is selected from the group consisting of—NR²—(C═O)—, —NR²—(C═S)—, —(C═O)—NR²—, and —(C═S)—NR²—; wherein eachoccurrence of L and W can be the same or different; R² is H or C₁-C₄alkyl; n is an integer selected from the group consisting of 1, 2, and3; Ch is a chelating agent that can comprise a metal; andpharmaceutically acceptable salts thereof.

In particular embodiments, R¹ is selected from the group consisting of:

In yet more particular embodiments, X is selected from the groupconsisting of ¹²⁵I, ¹²⁴I, ¹²³I, ¹³¹I, ²¹¹At, ⁷⁷Br, and ^(80m)Br. Incertain embodiments, at least one L is substituted arylene and X ishalogen.

In even yet more particular embodiments, the chelating agent is selectedfrom the group consisting of:

In certain embodiments, the metal chelating agent comprises a metalselected from the group consisting of: Y, Lu, Tc, Zr, In, Sm, Re, Cu,Pb, Ac, Bi, Al, Ga, Re, Ho and Sc, and radioisotopes thereof. In morecertain embodiments, the metal is ¹⁷⁵Lu.

In particular embodiments, the compound of formula (I) is selected fromthe group consisting of:

In more particular embodiments, X is ¹²⁵I or ²¹¹At.

In some embodiments, the compound of formula (I) has the followingformula:

wherein: Z is tetrazole or CO₂Q; Q is H or a protecting group; m is aninteger selected from the group consisting of 1, 2, 3, 4, and 5; R isindependently H or —CH₂—R¹; R¹ is selected from the group consisting of:

wherein X is selected from the group consisting of a radioisotope ofiodine, a radioisotope of bromine, and a radioisotope of astatine; L isa linker selected from the group consisting of C₁-C₆ alkylene, includingC₁, C₂, C₃, C₄, C₅, and C₆ alkylene, C₃-C₆ cycloalkylene, including C₃,C₄, C₅, and C₆ cycloalkylene, and arylene; W is selected from the groupconsisting of —NR²—(C═O)—, —NR²—(C═S)—, —(C═O)—NR²—, and —(C═S)—NR²—;wherein each occurrence of L and W can be the same or different; R² is Hor a C₁-C₄ alkyl, including C₁, C₂, C₃, and C₄ alkyl; n is an integerselected from the group consisting of 1, 2, and 3; Ch is a chelatingagent that can comprise a metal; and pharmaceutically acceptable saltsthereof.

In particular embodiments, the compound of formula (I) has the followingformula:

wherein L is selected from C₁, C₂, C₃, C₄, C₅, and C₆ alkylene; whereinX₁ is —CR³, —C—X, or N, wherein R³ is H or C₁-C₄ alkyl; and wherein X isselected from the group consisting of a radioisotope of iodine, aradioisotope of bromine, and a radioisotope of astatine.

In more particular embodiments, the compound of formula (I) is:

wherein X is ¹²⁵I or ²¹¹At.

In other embodiments, the compound of formula (I) has the followingformula:

wherein: p is an integer selected from the group consisting of 1, 2, 3,4, 5, and 6; and X is halogen; X₁ is —CR³, —C—X, or N, wherein R³ is Hor C₁-C₄ alkyl; and X₂ is selected from the group consisting of aradioisotope of iodine, a radioisotope of bromine, and a radioisotope ofastatine; and wherein M⁺ is a metal, which can be present or absent. Inparticular embodiments, M⁺ is a metal selected from the group consistingof: Y, Lu, Tc, Zr, In, Sm, Re, Cu, Pb, Ac, Bi, Al, Ga, Re, Ho and Sc,and radioisotopes thereof.

In certain embodiments, the compound of formula (I) is selected from thegroup consisting of:

In some embodiments, the one or more PSMA-expressing tumor or cells isselected from the group consisting of: a prostate tumor or cell, ametastasized prostate tumor or cell, a lung tumor or cell, a renal tumoror cell, a glioblastoma, a pancreatic tumor or cell, a bladder tumor orcell, a sarcoma, a melanoma, a breast tumor or cell, a colon tumor orcell, a germ cell, a pheochromocytoma, an esophageal tumor or cells, astomach tumor or cell, and combinations thereof.

In certain embodiments, the one or more PSMA-expressing tumor or cellsis a prostate tumor or cell. In some embodiments, the one or morePSMA-expressing tumor or cell is in vitro, in vivo, or ex vivo. Inparticular embodiments, the one or more PSMA-expressing tumor or cellsis present in a subject. In yet more particular embodiments, the subjectis human.

In some embodiments, the method of treatment results in inhibition oftumor growth.

In certain embodiments, the method further comprises administering ablocking agent in combination with the compound of formula (I), whereinthe blocking agent is a competitive PSMA ligand that reducesaccumulation of the compound of formula (I) in one or more PSMAexpressing cells in an off-target organ. In particular embodiments, theoff-target organ is selected from the group consisting of blood,stomach, spleen, thyroid gland, salivary gland, lacrimal gland, andkidney. In yet more particular embodiments, the off-target organ is thekidney or salivary gland.

In certain embodiments, the blocking agent comprises a PSMA-basedblocking agent, e.g., a competitive PSMA ligand. In more certainembodiments, the PSMA-based blocking agent is a compound of formula (I)that is not radiohalogenated, wherein the compound of formula (I) usedas a blocking agent and the compound of formula (I) used as atherapeutic agent can be the same or different.

In particular embodiments, the PSMA-based blocking agent is:

and related compounds disclosed in International PCT Patent ApplicationPublication No. WO/2017/070482, to Pomper et al., published Apr. 27,2017, which is incorporated herein by reference in its entirety, whereinX is a halogen, including iodine.

The term “combination” is used in its broadest sense and means that asubject is administered at least two agents, more particularly acompound of formula (I), and optionally, one or more other agents, e.g.,a blocking agent. More particularly, the term “in combination” refers tothe concomitant administration of two (or more) agents for the treatmentof a, e.g., single disease state. As used herein, the agents may becombined and administered in a single dosage form, may be administeredas separate dosage forms at the same time, or may be administered asseparate dosage forms that are administered sequentially. In suchembodiments, the blocking agent can be administered at the same time asthe radiotherapeutic compound of formula (I) or prior to administeringthe radiotherapeutic compound of formula (I). Accordingly, in someembodiments, the blocking agent is administered concurrently with theradiotherapeutic compound of formula (I), in some embodiments, 30minutes before administering the compound of formula (I), and in someembodiments, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15,14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 minute beforeadministering the compound of formula (I).

As used herein, the terms “treat,” treating,” “treatment,” and the like,are meant to decrease, suppress, attenuate, diminish, arrest, theunderlying cause of a disease, disorder, or condition, or to stabilizethe development or progression of a disease, disorder, condition, and/orsymptoms associated therewith. The terms “treat,” “treating,”“treatment,” and the like, as used herein can refer to curative therapy,prophylactic therapy, and preventative therapy. The treatment,administration, or therapy can be consecutive or intermittent.Consecutive treatment, administration, or therapy refers to treatment onat least a daily basis without interruption in treatment by one or moredays. Intermittent treatment or administration, or treatment oradministration in an intermittent fashion, refers to treatment that isnot consecutive, but rather cyclic in nature. Treatment according to thepresently disclosed methods can result in complete relief or cure from adisease, disorder, or condition, or partial amelioration of one or moresymptoms of the disease, disease, or condition, and can be temporary orpermanent. The term “treatment” also is intended to encompassprophylaxis, therapy and cure.

“Contacting” means any action which results in at least one compoundcomprising the treating agent of the presently disclosed subject matterphysically contacting at least one or more PSMA-expressing tumors orcells. Contacting can include exposing the PSMA-expressing tumors orcells to the compound in an amount sufficient to result in contact of atleast one compound with at least one PSMA-expressing tumor or cell.

By “agent” is meant a compound of formula (I) or another agent, e.g., apeptide, nucleic acid molecule, or other small molecule compoundadministered in combination with a compound of formula (I).

More particularly, the term “therapeutic agent” means a substance thathas the potential of affecting the function of an organism. Such anagent may be, for example, a naturally occurring, semi-synthetic, orsynthetic agent. For example, the therapeutic agent may be a drug thattargets a specific function of an organism. A therapeutic agent also maybe an antibiotic or a nutrient. A therapeutic agent may decrease,suppress, attenuate, diminish, arrest, or stabilize the development orprogression of disease, disorder, or condition in a host organism.

In general, the “effective amount” of an active agent refers to theamount necessary to elicit the desired biological response. As will beappreciated by those of ordinary skill in this art, the effective amountof an agent or device may vary depending on such factors as the desiredbiological endpoint, the agent to be delivered, the makeup of thepharmaceutical composition, the target tissue, and the like.

In other embodiments, the one or more PSMA-expressing tumor or cell isselected from the group consisting of: a prostate tumor or cell, ametastasized prostate tumor or cell, a lung tumor or cell, a renal tumoror cell, a glioblastoma, a pancreatic tumor or cell, a bladder tumor orcell, a sarcoma, a melanoma, a breast tumor or cell, a colon tumor orcell, a germ cell, a pheochromocytoma, an esophageal tumor or cell, astomach tumor or cell, and combinations thereof. In more specificembodiments, the one or more PSMA-expressing tumor or cell is a prostatetumor or cell. In some embodiments, the one or more PSMA-expressingtumors or cells are in vitro, in vivo, or ex vivo. In particularembodiments, the one or more PSMA-expressing tumors or cells are presentin a subject.

The “subject” treated by the presently disclosed methods in their manyembodiments is desirably a human subject, although it is to beunderstood that the methods described herein are effective with respectto all vertebrate species, which are intended to be included in the term“subject.” Accordingly, a “subject” can include a human subject formedical purposes, such as for the treatment of an existing condition ordisease or the prophylactic treatment for preventing the onset of acondition or disease, or an animal subject for medical, veterinarypurposes, or developmental purposes. Suitable animal subjects includemammals including, but not limited to, primates, e.g., humans, monkeys,apes, and the like; bovines, e.g., cattle, oxen, and the like; ovines,e.g., sheep and the like; caprines, e.g., goats and the like; porcines,e.g., pigs, hogs, and the like; equines, e.g., horses, donkeys, zebras,and the like; felines, including wild and domestic cats; canines,including dogs; lagomorphs, including rabbits, hares, and the like; androdents, including mice, rats, and the like. An animal may be atransgenic animal. In some embodiments, the subject is a humanincluding, but not limited to, fetal, neonatal, infant, juvenile, andadult subjects. Further, a “subject” can include a patient afflictedwith or suspected of being afflicted with a condition or disease. Thus,the terms “subject” and “patient” are used interchangeably herein. Theterm “subject” also refers to an organism, tissue, cell, or collectionof cells from a subject.

In some embodiments, the compound of formula (I) is cleared from thesubject's kidneys in about 24 hours.

In some embodiments, the presently disclosed methods use compounds thatare stable in vivo such that substantially all, e.g., more than about50%, 60%, 70%, 80%, or more preferably 90% of the injected compound isnot metabolized by the body prior to excretion. In other embodiments,the compound comprising the imaging agent is stable in vivo.

In specific embodiments, the method results in inhibition of the tumorgrowth. As used herein, the term “inhibition” or “reduction” andgrammatical derivations thereof, refers to the ability of an agent toblock, partially block, interfere, decrease, reduce or deactivate abiological molecule, pathway or mechanism of action. Thus, one ofordinary skill in the art would appreciate that the term “inhibit”encompasses a complete and/or partial loss of activity, e.g., a loss inactivity by at least 10%, in some embodiments, a loss in activity by atleast 20%, 30%, 50%, 75%, 95%, 98%, and up to and including 100%.

In other specific embodiments, the compound of formula (I) completelyoccupies the binding cavity of the PSMA expressing tumors or cells.

C. Methods of Imagining PSMA Expressing Tumors or Cells

In some aspects, the presently disclosed subject matter provides amethod for imaging one or more prostate-specific membrane antigen (PSMA)tumors or cells, the method comprising contacting the one or more tumorsor cells with an effective amount of a compound of formula (I) andmaking an image, wherein X of the compound of formula (I) is ¹²⁴I andthe imaging comprises positron emission tomography (PET).

D. One-Pot, Multi-Step Synthesis Method

In some embodiments, the presently disclosed subject matter provides aone-pot, multi-step synthesis method for preparing a radiotherapeuticcompound of formula (Ia):

wherein X is a radiohalide, the method comprising:

(a) providing a precursor compound of formula (Ia′):

(b) contacting the precursor compound of formula (Ia′) with solutioncomprising a radiohalide and N-chlorosuccinimide, followed by theaddition of glacial acetic acid to form a radiohalogenated precursorcompound of formula (Ia″):

(c) contacting the radiohalogenated precursor compound of formula (Ia″)with trifluoroacetic acid to form a radiohalogenated compound of formula(Ia′″):

(d) contacting the radiohalogenated compound of formula (Ia′″) withNaOAc and Lu(NO₃)₃ to form a radiotherapeutic compound of formula (Ia).

In some embodiments, the one-pot, multi-step synthesis method furthercomprises quenching step (d) with ethylenediaminetetraacetic acid(EDTA). In other embodiments, the one-pot, multi-step synthesis methodfurther comprises purifying the radiotherapeutic compound of formula(Ia) by radio-high-performance liquid chromatography (HPLC).

In certain embodiments of the one-pot, multi-step synthesis method, theradiohalide is selected from the group consisting of ¹²⁵I, ¹²³I, ¹³¹I,¹²⁴I, ²¹¹At, ⁷⁷Br, and ^(80m)Br. In yet more certain embodiments of theone-pot, multi-step synthesis method, the radiohalide is iodine-125(¹²⁵I) or astatine-211 (²¹¹At).

E. Pharmaceutical Composition Comprising Compounds of Formula (I)

In another aspect, the present disclosure provides a pharmaceuticalcomposition including one compound of formula (I) alone or incombination with one or more additional therapeutic agents in admixturewith a pharmaceutically acceptable excipient. One of skill in the artwill recognize that the pharmaceutical compositions include thepharmaceutically acceptable salts of the compounds described above.Pharmaceutically acceptable salts are generally well known to those ofordinary skill in the art, and include salts of active compounds whichare prepared with relatively nontoxic acids or bases, depending on theparticular substituent moieties found on the compounds described herein.When compounds of the present disclosure contain relatively acidicfunctionalities, base addition salts can be obtained by contacting theneutral form of such compounds with a sufficient amount of the desiredbase, either neat or in a suitable inert solvent or by ion exchange,whereby one basic counterion (base) in an ionic complex is substitutedfor another. Examples of pharmaceutically acceptable base addition saltsinclude sodium, potassium, calcium, ammonium, organic amino, ormagnesium salt, or a similar salt.

When compounds of the present disclosure contain relatively basicfunctionalities, acid addition salts can be obtained by contacting theneutral form of such compounds with a sufficient amount of the desiredacid, either neat or in a suitable inert solvent or by ion exchange,whereby one acidic counterion (acid) in an ionic complex is substitutedfor another. Examples of pharmaceutically acceptable acid addition saltsinclude those derived from inorganic acids like hydrochloric,hydrobromic, nitric, carbonic, monohydrogencarbonic, phosphoric,monohydrogenphosphoric, dihydrogenphosphoric, sulfuric,monohydrogensulfuric, hydriodic, or phosphorous acids and the like, aswell as the salts derived from relatively nontoxic organic acids likeacetic, propionic, isobutyric, maleic, malonic, benzoic, succinic,suberic, fumaric, lactic, mandelic, phthalic, benzenesulfonic,p-toluenesulfonic, citric, tartaric, methanesulfonic, and the like. Alsoincluded are salts of amino acids such as arginate and the like, andsalts of organic acids like glucuronic or galactunoric acids and thelike (see, for example, Berge et al, “Pharmaceutical Salts”, Journal ofPharmaceutical Science, 1977, 66, 1-19). Certain specific compounds ofthe present disclosure contain both basic and acidic functionalitiesthat allow the compounds to be converted into either base or acidaddition salts.

Accordingly, pharmaceutically acceptable salts suitable for use with thepresently disclosed subject matter include, by way of example but notlimitation, acetate, benzenesulfonate, benzoate, bicarbonate,bitartrate, bromide, calcium edetate, carnsylate, carbonate, citrate,edetate, edisylate, estolate, esylate, fumarate, gluceptate, gluconate,glutamate, glycollylarsanilate, hexylresorcinate, hydrabamine,hydrobromide, hydrochloride, hydroxynaphthoate, iodide, isethionate,lactate, lactobionate, malate, maleate, mandelate, mesylate, mucate,napsylate, nitrate, pamoate (embonate), pantothenate,phosphate/diphosphate, polygalacturonate, salicylate, stearate,subacetate, succinate, sulfate, tannate, tartrate, or teoclate. Otherpharmaceutically acceptable salts may be found in, for example,Remington: The Science and Practice of Pharmacy (20th ed.) Lippincott,Williams & Wilkins (2000).

In therapeutic and/or diagnostic applications, the compounds of thedisclosure can be formulated for a variety of modes of administration,including systemic and localized administration. Techniques andformulations generally may be found in Remington: The Science andPractice of Pharmacy (20th ed.) Lippincott, Williams & Wilkins (2000).

Depending on the specific conditions being treated, such agents may beformulated into liquid or solid dosage forms and administeredsystemically or locally. The agents may be delivered, for example, in atimed- or sustained-slow release form as is known to those skilled inthe art. Techniques for formulation and administration may be found inRemington: The Science and Practice of Pharmacy (20^(th) ed.)Lippincott, Williams & Wilkins (2000). Suitable routes may includeparenteral delivery, including intramuscular, subcutaneous,intramedullary injections, as well as intrathecal, directintraventricular, intravenous, intra-articullar, intra-sternal,intra-synovial, intra-hepatic, intralesional, intracranial,intraperitoneal, intranasal, or intraocular injections or other modes ofdelivery.

For injection, the agents of the disclosure may be formulated anddiluted in aqueous solutions, such as in physiologically compatiblebuffers such as Hank's solution, Ringer's solution, or physiologicalsaline buffer. For such transmucosal administration, penetrantsappropriate to the barrier to be permeated are used in the formulation.Such penetrants are generally known in the art.

Use of pharmaceutically acceptable inert carriers to formulate thecompounds herein disclosed for the practice of the disclosure intodosages suitable for systemic administration is within the scope of thedisclosure. With proper choice of carrier and suitable manufacturingpractice, the compositions of the present disclosure, in particular,those formulated as solutions, may be administered parenterally, such asby intravenous injection.

Pharmaceutical compositions suitable for use in the present disclosureinclude compositions wherein the active ingredients are contained in aneffective amount to achieve its intended purpose. Determination of theeffective amounts is well within the capability of those skilled in theart, especially in light of the detailed disclosure provided herein.Generally, the compounds according to the disclosure are effective overa wide dosage range. For example, in the treatment of adult humans,dosages from 0.01 to 1000 mg, from 0.5 to 100 mg, from 1 to 50 mg perday, and from 5 to 40 mg per day are examples of dosages that may beused. A non-limiting dosage is 10 to 30 mg per day. The exact dosagewill depend upon the route of administration, the form in which thecompound is administered, the subject to be treated, the body weight ofthe subject to be treated, the bioavailability of the compound(s), theadsorption, distribution, metabolism, and excretion (ADME) toxicity ofthe compound(s), and the preference and experience of the attendingphysician.

In addition to the active ingredients, these pharmaceutical compositionsmay contain suitable pharmaceutically acceptable carriers comprisingexcipients and auxiliaries, which facilitate processing of the activecompounds into preparations which can be used pharmaceutically.

In certain embodiments, the presently disclosed subject matter providesa kit for treating one or more PSMA expressing tumors or cells, the kitcomprising a compound of formula (I). In yet more certain embodiments,the kit further comprises a blocking agent.

II. Definitions

Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation. Unlessotherwise defined, all technical and scientific terms used herein havethe same meaning as commonly understood by one of ordinary skill in theart to which this presently described subject matter belongs.

While the following terms in relation to compounds of formula (I) arebelieved to be well understood by one of ordinary skill in the art, thefollowing definitions are set forth to facilitate explanation of thepresently disclosed subject matter. These definitions are intended tosupplement and illustrate, not preclude, the definitions that would beapparent to one of ordinary skill in the art upon review of the presentdisclosure.

The terms substituted, whether preceded by the term “optionally” or not,and substituent, as used herein, refer to the ability, as appreciated byone skilled in this art, to change one functional group for anotherfunctional group on a molecule, provided that the valency of all atomsis maintained. When more than one position in any given structure may besubstituted with more than one substituent selected from a specifiedgroup, the substituent may be either the same or different at everyposition. The substituents also may be further substituted (e.g., anaryl group substituent may have another substituent off it, such asanother aryl group, which is further substituted at one or morepositions).

Where substituent groups or linking groups are specified by theirconventional chemical formulae, written from left to right, they equallyencompass the chemically identical substituents that would result fromwriting the structure from right to left, e.g., —CH₂O— is equivalent to—OCH₂—; —C(═O)O— is equivalent to —OC(═O)—; —OC(═O)NR— is equivalent to—NRC(═O)O—, and the like.

When the term “independently selected” is used, the substituents beingreferred to (e.g., R groups, such as groups R₁, R₂, and the like, orvariables, such as “m” and “n”), can be identical or different. Forexample, both R₁ and R₂ can be substituted alkyls, or R₁ can be hydrogenand R₂ can be a substituted alkyl, and the like.

The terms “a,” “an,” or “a(n),” when used in reference to a group ofsubstituents herein, mean at least one. For example, where a compound issubstituted with “an” alkyl or aryl, the compound is optionallysubstituted with at least one alkyl and/or at least one aryl. Moreover,where a moiety is substituted with an R substituent, the group may bereferred to as “R-substituted.” Where a moiety is R-substituted, themoiety is substituted with at least one R substituent and each Rsubstituent is optionally different.

A named “R” or group will generally have the structure that isrecognized in the art as corresponding to a group having that name,unless specified otherwise herein. For the purposes of illustration,certain representative “R” groups as set forth above are defined below.

Description of compounds of the present disclosure is limited byprinciples of chemical bonding known to those skilled in the art.Accordingly, where a group may be substituted by one or more of a numberof substituents, such substitutions are selected so as to comply withprinciples of chemical bonding and to give compounds which are notinherently unstable and/or would be known to one of ordinary skill inthe art as likely to be unstable under ambient conditions, such asaqueous, neutral, and several known physiological conditions. Forexample, a heterocycloalkyl or heteroaryl is attached to the remainderof the molecule via a ring heteroatom in compliance with principles ofchemical bonding known to those skilled in the art thereby avoidinginherently unstable compounds.

Unless otherwise explicitly defined, a “substituent group,” as usedherein, includes a functional group selected from one or more of thefollowing moieties, which are defined herein:

The term hydrocarbon, as used herein, refers to any chemical groupcomprising hydrogen and carbon. The hydrocarbon may be substituted orunsubstituted. As would be known to one skilled in this art, allvalencies must be satisfied in making any substitutions. The hydrocarbonmay be unsaturated, saturated, branched, unbranched, cyclic, polycyclic,or heterocyclic. Illustrative hydrocarbons are further defined hereinbelow and include, for example, methyl, ethyl, n-propyl, isopropyl,cyclopropyl, allyl, vinyl, n-butyl, tert-butyl, ethynyl, cyclohexyl, andthe like.

The term “alkyl,” by itself or as part of another substituent, means,unless otherwise stated, a straight (i.e., unbranched) or branchedchain, acyclic or cyclic hydrocarbon group, or combination thereof,which may be fully saturated, mono- or polyunsaturated and can includedi- and multivalent groups, having the number of carbon atoms designated(i.e., C₁-C₁₀ means one to ten carbons, including 1, 2, 3, 4, 5, 6, 7,8, 9, and 10 carbons). In particular embodiments, the term “alkyl”refers to C₁₋₂₀ inclusive, including 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,12, 13, 14, 15, 16, 17, 18, 19, and 20 carbons, linear (i.e.,“straight-chain”), branched, or cyclic, saturated or at least partiallyand in some cases fully unsaturated (i.e., alkenyl and alkynyl)hydrocarbon radicals derived from a hydrocarbon moiety containingbetween one and twenty carbon atoms by removal of a single hydrogenatom.

Representative saturated hydrocarbon groups include, but are not limitedto, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl,tert-butyl, n-pentyl, sec-pentyl, isopentyl, neopentyl, n-hexyl,sec-hexyl, n-heptyl, n-octyl, n-decyl, n-undecyl, dodecyl, cyclohexyl,(cyclohexyl)methyl, cyclopropylmethyl, and homologs and isomers thereof.

“Branched” refers to an alkyl group in which a lower alkyl group, suchas methyl, ethyl or propyl, is attached to a linear alkyl chain. “Loweralkyl” refers to an alkyl group having 1 to about 8 carbon atoms (i.e.,a C₁₋₈ alkyl), e.g., 1, 2, 3, 4, 5, 6, 7, or 8 carbon atoms. “Higheralkyl” refers to an alkyl group having about 10 to about 20 carbonatoms, e.g., 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbon atoms.In certain embodiments, “alkyl” refers, in particular, to C₁₋₈straight-chain alkyls. In other embodiments, “alkyl” refers, inparticular, to C₁₋₈ branched-chain alkyls.

Alkyl groups can optionally be substituted (a “substituted alkyl”) withone or more alkyl group substituents, which can be the same ordifferent. The term “alkyl group substituent” includes but is notlimited to alkyl, substituted alkyl, halo, acylamino, acyl, hydroxyl,aryloxyl, alkoxyl, alkylthio, arylthio, aralkyloxyl, aralkylthio,carboxyl, alkoxycarbonyl, oxo, and cycloalkyl. There can be optionallyinserted along the alkyl chain one or more oxygen, sulfur or substitutedor unsubstituted nitrogen atoms, wherein the nitrogen substituent ishydrogen, lower alkyl (also referred to herein as “alkylaminoalkyl”), oraryl.

Thus, as used herein, the term “substituted alkyl” includes alkylgroups, as defined herein, in which one or more atoms or functionalgroups of the alkyl group are replaced with another atom or functionalgroup, including for example, alkyl, substituted alkyl, halogen, aryl,substituted aryl, alkoxyl, hydroxyl, nitro, amino, alkylamino,dialkylamino, sulfate, and mercapto.

The term “heteroalkyl,” by itself or in combination with another term,means, unless otherwise stated, a stable straight or branched chain, orcyclic hydrocarbon group, or combinations thereof, consisting of atleast one carbon atoms and at least one heteroatom selected from thegroup consisting of O, N, P, Si and S, and wherein the nitrogen,phosphorus, and sulfur atoms may optionally be oxidized and the nitrogenheteroatom may optionally be quaternized. The heteroatom(s) 0, N, P andS and Si may be placed at any interior position of the heteroalkyl groupor at the position at which alkyl group is attached to the remainder ofthe molecule. Examples include, but are not limited to, —CH₂—CH₂—O—CH₃,—CH₂—CH₂—NH—CH₃, —CH₂—CH₂—N(CH₃)—CH₃, —CH₂—S—CH₂—CH₃,—CH₂—CH₂₅—S(O)—CH₃, —CH₂—CH₂—S(O)₂—CH₃, —CH═CH—O—CH₃, —Si(CH₃)₃,—CH₂—CH═N—OCH₃, —CH═CH—N(CH₃)— CH₃, O—CH₃, —O—CH₂—CH₃, and —CN. Up totwo or three heteroatoms may be consecutive, such as, for example,—CH₂—NH—OCH₃ and —CH₂—O—Si(CH₃)₃.

As described above, heteroalkyl groups, as used herein, include thosegroups that are attached to the remainder of the molecule through aheteroatom, such as —C(O)NR′, —NR′R″, —OR′, —SR, —S(O)R, and/or—S(O₂)R′. Where “heteroalkyl” is recited, followed by recitations ofspecific heteroalkyl groups, such as —NR′R or the like, it will beunderstood that the terms heteroalkyl and —NR′R″ are not redundant ormutually exclusive. Rather, the specific heteroalkyl groups are recitedto add clarity. Thus, the term “heteroalkyl” should not be interpretedherein as excluding specific heteroalkyl groups, such as —NR′R″ or thelike.

“Cyclic” and “cycloalkyl” refer to a non-aromatic mono- or multicyclicring system of about 3 to about 10 carbon atoms, e.g., 3, 4, 5, 6, 7, 8,9, or 10 carbon atoms. The cycloalkyl group can be optionally partiallyunsaturated. The cycloalkyl group also can be optionally substitutedwith an alkyl group substituent as defined herein, oxo, and/or alkylene.There can be optionally inserted along the cyclic alkyl chain one ormore oxygen, sulfur or substituted or unsubstituted nitrogen atoms,wherein the nitrogen substituent is hydrogen, unsubstituted alkyl,substituted alkyl, aryl, or substituted aryl, thus providing aheterocyclic group. Representative monocyclic cycloalkyl rings includecyclopentyl, cyclohexyl, and cycloheptyl. Multicyclic cycloalkyl ringsinclude adamantyl, octahydronaphthyl, decalin, camphor, camphane, andnoradamantyl, and fused ring systems, such as dihydro- andtetrahydronaphthalene, and the like.

The term “cycloalkylalkyl,” as used herein, refers to a cycloalkyl groupas defined hereinabove, which is attached to the parent molecular moietythrough an alkyl group, also as defined above. Examples ofcycloalkylalkyl groups include cyclopropylmethyl and cyclopentylethyl.

The terms “cycloheteroalkyl” or “heterocycloalkyl” refer to anon-aromatic ring system, unsaturated or partially unsaturated ringsystem, such as a 3- to 10-member substituted or unsubstitutedcycloalkyl ring system, including one or more heteroatoms, which can bethe same or different, and are selected from the group consisting ofnitrogen (N), oxygen (O), sulfur (S), phosphorus (P), and silicon (Si),and optionally can include one or more double bonds.

The cycloheteroalkyl ring can be optionally fused to or otherwiseattached to other cycloheteroalkyl rings and/or non-aromatic hydrocarbonrings. Heterocyclic rings include those having from one to threeheteroatoms independently selected from oxygen, sulfur, and nitrogen, inwhich the nitrogen and sulfur heteroatoms may optionally be oxidized andthe nitrogen heteroatom may optionally be quaternized. In certainembodiments, the term heterocylic refers to a non-aromatic 5-, 6-, or7-membered ring or a polycyclic group wherein at least one ring atom isa heteroatom selected from O, S, and N (wherein the nitrogen and sulfurheteroatoms may be optionally oxidized), including, but not limited to,a bi- or tri-cyclic group, comprising fused six-membered rings havingbetween one and three heteroatoms independently selected from theoxygen, sulfur, and nitrogen, wherein (i) each 5-membered ring has 0 to2 double bonds, each 6-membered ring has 0 to 2 double bonds, and each7-membered ring has 0 to 3 double bonds, (ii) the nitrogen and sulfurheteroatoms may be optionally oxidized, (iii) the nitrogen heteroatommay optionally be quaternized, and (iv) any of the above heterocyclicrings may be fused to an aryl or heteroaryl ring. Representativecycloheteroalkyl ring systems include, but are not limited topyrrolidinyl, pyrrolinyl, imidazolidinyl, imidazolinyl, pyrazolidinyl,pyrazolinyl, piperidyl, piperazinyl, indolinyl, quinuclidinyl,morpholinyl, thiomorpholinyl, thiadiazinanyl, tetrahydrofuranyl, and thelike.

The terms “cycloalkyl” and “heterocycloalkyl”, by themselves or incombination with other terms, represent, unless otherwise stated, cyclicversions of “alkyl” and “heteroalkyl”, respectively. Additionally, forheterocycloalkyl, a heteroatom can occupy the position at which theheterocycle is attached to the remainder of the molecule. Examples ofcycloalkyl include, but are not limited to, cyclopentyl, cyclohexyl,1-cyclohexenyl, 3-cyclohexenyl, cycloheptyl, and the like. Examples ofheterocycloalkyl include, but are not limited to,1-(1,2,5,6-tetrahydropyridyl), 1-piperidinyl, 2-piperidinyl,3-piperidinyl, 4-morpholinyl, 3-morpholinyl, tetrahydrofuran-2-yl,tetrahydrofuran-3-yl, tetrahydrothien-2-yl, tetrahydrothien-3-yl,1-piperazinyl, 2-piperazinyl, and the like. The terms “cycloalkylene”and “heterocycloalkylene” refer to the divalent derivatives ofcycloalkyl and heterocycloalkyl, respectively. Accordingly,“cycloalkylene” can include C₃-C₆ cycloalkylene, including C₃, C₄, C₅,and C₆ cycloalkylene, such as cyclopropylene, cyclobutylene,cyclopentylene, and cyclohexylene, each of which can be substituted orunsubstituted.

An unsaturated alkyl group is one having one or more double bonds ortriple bonds. Examples of unsaturated alkyl groups include, but are notlimited to, vinyl, 2-propenyl, crotyl, 2-isopentenyl, 2-(butadienyl),2,4-pentadienyl, 3-(1,4-pentadienyl), ethynyl, 1- and 3-propynyl,3-butynyl, and the higher homologs and isomers. Alkyl groups that arelimited to hydrocarbon groups are termed “homoalkyl.”

More particularly, the term “alkenyl” as used herein refers to amonovalent group derived from a C₁₋₂₀, including C₁, C₂, C₃, C₄, C₅, C₆,C₇, C₈, C₉, C₁₀, C₁₁, C₁₂, C₁₃, C₁₄, C₁₅, C₁₆, C₁₇, C₁₈, C₁₉, and C₂₀,inclusive straight or branched hydrocarbon moiety having at least onecarbon-carbon double bond by the removal of a single hydrogen molecule.Alkenyl groups include, for example, ethenyl (i.e., vinyl), propenyl,butenyl, 1-methyl-2-buten-1-yl, pentenyl, hexenyl, octenyl, allenyl, andbutadienyl.

The term “cycloalkenyl” as used herein refers to a cyclic hydrocarboncontaining at least one carbon-carbon double bond. Examples ofcycloalkenyl groups include cyclopropenyl, cyclobutenyl, cyclopentenyl,cyclopentadiene, cyclohexenyl, 1,3-cyclohexadiene, cycloheptenyl,cycloheptatrienyl, and cyclooctenyl.

The term “alkynyl” as used herein refers to a monovalent group derivedfrom a straight or branched C₁₋₂₀ hydrocarbon of a designed number ofcarbon atoms containing at least one carbon-carbon triple bond. Examplesof “alkynyl” include ethynyl, 2-propynyl (propargyl), 1-propynyl,pentynyl, hexynyl, and heptynyl groups, and the like.

The term “alkylene” by itself or a part of another substituent refers toa straight or branched bivalent aliphatic hydrocarbon group derived froman alkyl group having from 1 to about 20 carbon atoms, e.g., 1, 2, 3, 4,5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbonatoms. The alkylene group can be straight, branched or cyclic. Thealkylene group also can be optionally unsaturated and/or substitutedwith one or more “alkyl group substituents.” There can be optionallyinserted along the alkylene group one or more oxygen, sulfur orsubstituted or unsubstituted nitrogen atoms (also referred to herein as“alkylaminoalkyl”), wherein the nitrogen substituent is alkyl aspreviously described. Exemplary alkylene groups include methylene(—CH₂—); ethylene (—CH₂—CH₂—); propylene (—(CH₂)₃—); cyclohexylene(—C₆H₁₀—); —CH═CH—CH═CH; —CH═CH—CH₂—; —CH₂CH₂CH₂CH₂—, —CH₂CH═CHCH₂—,—CH₂CsCCH₂—, —CH₂CH₂CH(CH₂CH₂CH₃)CH₂—, —(CH₂)_(q)—N(R)—(CH₂)_(r)—,wherein each of q and r is independently an integer from 0 to about 20,e.g., 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,19, or 20, and R is hydrogen or lower alkyl; methylenedioxyl(—O—CH₂—O—); and ethylenedioxyl (—O—(CH₂)₂—O—). An alkylene group canhave about 2 to about 3 carbon atoms and can further have 6-20 carbons.Typically, an alkyl (or alkylene) group will have from 1 to 24 carbonatoms, with those groups having 10 or fewer carbon atoms being someembodiments of the present disclosure. A “lower alkyl” or “loweralkylene” is a shorter chain alkyl or alkylene group, generally havingeight or fewer carbon atoms.

The term “heteroalkylene” by itself or as part of another substituentmeans a divalent group derived from heteroalkyl, as exemplified, but notlimited by, —CH₂—CH₂—S—CH₂—CH₂— and —CH₂—S—CH₂—CH₂—NH—CH₂—. Forheteroalkylene groups, heteroatoms also can occupy either or both of thechain termini (e.g., alkyleneoxo, alkylenedioxo, alkyleneamino,alkylenediamino, and the like). Still further, for alkylene andheteroalkylene linking groups, no orientation of the linking group isimplied by the direction in which the formula of the linking group iswritten. For example, the formula —C(O)OR′— represents both —C(O)OR′—and —R′OC(O)—.

The term “aryl” means, unless otherwise stated, an aromatic hydrocarbonsubstituent that can be a single ring or multiple rings (such as from 1to 3 rings), which are fused together or linked covalently. The term“heteroaryl” refers to aryl groups (or rings) that contain from one tofour heteroatoms (in each separate ring in the case of multiple rings)selected from N, O, and S, wherein the nitrogen and sulfur atoms areoptionally oxidized, and the nitrogen atom(s) are optionallyquaternized. A heteroaryl group can be attached to the remainder of themolecule through a carbon or heteroatom. Non-limiting examples of aryland heteroaryl groups include phenyl, 1-naphthyl, 2-naphthyl,4-biphenyl, 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 3-pyrazolyl,2-imidazolyl, 4-imidazolyl, pyrazinyl, 2-oxazolyl, 4-oxazolyl,2-phenyl-4-oxazolyl, 5-oxazolyl, 3-isoxazolyl, 4-isoxazolyl,5-isoxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 2-furyl, 3-furyl,2-thienyl, 3-thienyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrimidyl,4-pyrimidyl, 5-benzothiazolyl, purinyl, 2-benzimidazolyl, 5-indolyl,1-isoquinolyl, 5-isoquinolyl, 2-quinoxalinyl, 5-quinoxalinyl,3-quinolyl, and 6-quinolyl. Substituents for each of above noted aryland heteroaryl ring systems are selected from the group of acceptablesubstituents described below. The terms “arylene” and “heteroarylene”refer to the divalent forms of aryl and heteroaryl, respectively.

For brevity, the term “aryl” when used in combination with other terms(e.g., aryloxy, arylthioxy, arylalkyl) includes both aryl and heteroarylrings as defined above. Thus, the terms “arylalkyl” and“heteroarylalkyl” are meant to include those groups in which an aryl orheteroaryl group is attached to an alkyl group (e.g., benzyl, phenethyl,pyridylmethyl, furylmethyl, and the like) including those alkyl groupsin which a carbon atom (e.g., a methylene group) has been replaced by,for example, an oxygen atom (e.g., phenoxymethyl, 2-pyridyloxymethyl,3-(1-naphthyloxy)propyl, and the like). However, the term “haloaryl,” asused herein is meant to cover only aryls substituted with one or morehalogens.

Where a heteroalkyl, heterocycloalkyl, or heteroaryl includes a specificnumber of members (e.g. “3 to 7 membered”), the term “member” refers toa carbon or heteroatom.

Further, a structure represented generally by the formula:

as used herein refers to a ring structure, for example, but not limitedto a 3-carbon, a 4-carbon, a 5-carbon, a 6-carbon, a 7-carbon, and thelike, aliphatic and/or aromatic cyclic compound, including a saturatedring structure, a partially saturated ring structure, and an unsaturatedring structure, comprising a substituent R group, wherein the R groupcan be present or absent, and when present, one or more R groups caneach be substituted on one or more available carbon atoms of the ringstructure. The presence or absence of the R group and number of R groupsis determined by the value of the variable “n,” which is an integergenerally having a value ranging from 0 to the number of carbon atoms onthe ring available for substitution. Each R group, if more than one, issubstituted on an available carbon of the ring structure rather than onanother R group. For example, the structure above where n is 0 to 2would comprise compound groups including, but not limited to:

and the like.

A dashed line representing a bond in a cyclic ring structure indicatesthat the bond can be either present or absent in the ring. That is, adashed line representing a bond in a cyclic ring structure indicatesthat the ring structure is selected from the group consisting of asaturated ring structure, a partially saturated ring structure, and anunsaturated ring structure.

The symbol (

) denotes the point of attachment of a moiety to the remainder of themolecule.

When a named atom of an aromatic ring or a heterocyclic aromatic ring isdefined as being “absent,” the named atom is replaced by a direct bond.

Each of above terms (e.g., “alkyl,” “heteroalkyl,” “cycloalkyl, and“heterocycloalkyl”, “aryl,” “heteroaryl,” “phosphonate,” and “sulfonate”as well as their divalent derivatives) are meant to include bothsubstituted and unsubstituted forms of the indicated group. Optionalsubstituents for each type of group are provided below.

Substituents for alkyl, heteroalkyl, cycloalkyl, heterocycloalkylmonovalent and divalent derivative groups (including those groups oftenreferred to as alkylene, alkenyl, heteroalkylene, heteroalkenyl,alkynyl, cycloalkyl, heterocycloalkyl, cycloalkenyl, andheterocycloalkenyl) can be one or more of a variety of groups selectedfrom, but not limited to: —OR′, ═O, ═NR′, ═N—OR′, —NR′R″, —SR′,-halogen, —SiR′R″R′″, —OC(O)R′, —C(O)R′, —CO₂R′, —C(O)NR′R″,—OC(O)NR′R″, —NR″C(O)R′, —NR′—C(O)NR″R′″, —NR″C(O)OR′,—NR—C(NR′R″)═NR′″, —S(O)R′, —S(O)₂R′, —S(O)₂NR′R″, —NRSO₂R′, —CN and—NO₂ in a number ranging from zero to (2m′+1), where m′ is the totalnumber of carbon atoms in such groups. R′, R″, R′″ and R″″ each mayindependently refer to hydrogen, substituted or unsubstitutedheteroalkyl, substituted or unsubstituted cycloalkyl, substituted orunsubstituted heterocycloalkyl, substituted or unsubstituted aryl (e.g.,aryl substituted with 1-3 halogens), substituted or unsubstituted alkyl,alkoxy or thioalkoxy groups, or arylalkyl groups. As used herein, an“alkoxy” group is an alkyl attached to the remainder of the moleculethrough a divalent oxygen. When a compound of the disclosure includesmore than one R group, for example, each of the R groups isindependently selected as are each R′, R″, R″ and R″″ groups when morethan one of these groups is present. When R′ and R″ are attached to thesame nitrogen atom, they can be combined with the nitrogen atom to forma 4-, 5-, 6-, or 7-membered ring. For example, —NR′R″ is meant toinclude, but not be limited to, 1-pyrrolidinyl and 4-morpholinyl. Fromthe above discussion of substituents, one of skill in the art willunderstand that the term “alkyl” is meant to include groups includingcarbon atoms bound to groups other than hydrogen groups, such ashaloalkyl (e.g., —CF₃ and —CH₂CF₃) and acyl (e.g., —C(O)CH₃, —C(O)CF₃,—C(O)CH₂OCH₃, and the like).

Similar to the substituents described for alkyl groups above, exemplarysubstituents for aryl and heteroaryl groups (as well as their divalentderivatives) are varied and are selected from, for example: halogen,—OR′, —NR′R″, —SR′, —SiR′R″R′″, —OC(O)R′, —C(O)R′, —CO₂R′, —C(O)NR′R″,—OC(O)NR′R″, —NR″C(O)R′, —NR′—C(O)NR″R′″, —NR″C(O)OR′,—NR—C(NR′R″R′″)═NR′″, —NR—C(NR′R″)═NR′″-S(O)R′, —S(O)₂R′, —S(O)₂NR′R″,—NRSO₂R′, —CN and —NO₂, —R′, —N₃, —CH(Ph)₂, fluoro(C₁-C₄)alkoxo, andfluoro(C₁-C₄)alkyl, in a number ranging from zero to the total number ofopen valences on aromatic ring system; and where R′, R″, R″ and R″″ maybe independently selected from hydrogen, substituted or unsubstitutedalkyl, substituted or unsubstituted heteroalkyl, substituted orunsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl,substituted or unsubstituted aryl and substituted or unsubstitutedheteroaryl. When a compound of the disclosure includes more than one Rgroup, for example, each of the R groups is independently selected asare each R′, R″, R″ and R″″ groups when more than one of these groups ispresent.

Two of the substituents on adjacent atoms of aryl or heteroaryl ring mayoptionally form a ring of the formula -T-C(O)—(CRR′)_(q)—U—, wherein Tand U are independently —NR—, —O—, —CRR′— or a single bond, and q is aninteger of from 0 to 3. Alternatively, two of the substituents onadjacent atoms of aryl or heteroaryl ring may optionally be replacedwith a substituent of the formula -A-(CH₂)_(r)—B—, wherein A and B areindependently —CRR′—, —O—, —NR—, —S—, —S(O)—, —S(O)₂—, —S(O)₂NR′— or asingle bond, and r is an integer of from 1 to 4.

One of the single bonds of the new ring so formed may optionally bereplaced with a double bond. Alternatively, two of the substituents onadjacent atoms of aryl or heteroaryl ring may optionally be replacedwith a substituent of the formula —(CRR′)_(s)—X′— (C″R′″)_(d)—, where sand d are independently integers of from 0 to 3, and X′ is —O—, —NR′—,—S—, —S(O)—, —S(O)₂—, or —S(O)₂NR′—. The substituents R, R′, R″ and R′″may be independently selected from hydrogen, substituted orunsubstituted alkyl, substituted or unsubstituted cycloalkyl,substituted or unsubstituted heterocycloalkyl, substituted orunsubstituted aryl, and substituted or unsubstituted heteroaryl.

As used herein, the term “acyl” refers to an organic acid group whereinthe —OH of the carboxyl group has been replaced with another substituentand has the general formula RC(═O)—, wherein R is an alkyl, alkenyl,alkynyl, aryl, carbocylic, heterocyclic, or aromatic heterocyclic groupas defined herein). As such, the term “acyl” specifically includesarylacyl groups, such as a 2-(furan-2-yl)acetyl)- and a 2-phenylacetylgroup. Specific examples of acyl groups include acetyl and benzoyl. Acylgroups also are intended to include amides, —RC(═O)NR′, esters,—RC(═O)OR′, ketones, —RC(═O)R′, and aldehydes, —RC(═O)H.

The terms “alkoxyl” or “alkoxy” are used interchangeably herein andrefer to a saturated (i.e., alkyl-O—) or unsaturated (i.e., alkenyl-O—and alkynyl-O—) group attached to the parent molecular moiety through anoxygen atom, wherein the terms “alkyl,” “alkenyl,” and “alkynyl” are aspreviously described and can include C₁₋₂₀ inclusive, linear, branched,or cyclic, saturated or unsaturated oxo-hydrocarbon chains, including,for example, methoxyl, ethoxyl, propoxyl, isopropoxyl, n-butoxyl,sec-butoxyl, tert-butoxyl, and n-pentoxyl, neopentoxyl, n-hexoxyl, andthe like.

The term “alkoxyalkyl” as used herein refers to an alkyl-O-alkyl ether,for example, a methoxyethyl or an ethoxymethyl group.

“Aryloxyl” refers to an aryl-O— group wherein the aryl group is aspreviously described, including a substituted aryl. The term “aryloxyl”as used herein can refer to phenyloxyl or hexyloxyl, and alkyl,substituted alkyl, halo, or alkoxyl substituted phenyloxyl or hexyloxyl.

“Aralkyl” refers to an aryl-alkyl-group wherein aryl and alkyl are aspreviously described, and included substituted aryl and substitutedalkyl. Exemplary aralkyl groups include benzyl, phenylethyl, andnaphthylmethyl.

“Aralkyloxyl” refers to an aralkyl-O— group wherein the aralkyl group isas previously described. An exemplary aralkyloxyl group is benzyloxyl,i.e., C₆H₅—CH₂—O—. An aralkyloxyl group can optionally be substituted.

“Alkoxycarbonyl” refers to an alkyl-O—C(═O)— group. Exemplaryalkoxycarbonyl groups include methoxycarbonyl, ethoxycarbonyl,butyloxycarbonyl, and tert-butyloxycarbonyl.

“Aryloxycarbonyl” refers to an aryl-O—C(═O)— group. Exemplaryaryloxycarbonyl groups include phenoxy- and naphthoxy-carbonyl.

“Aralkoxycarbonyl” refers to an aralkyl-O—C(═O)— group. An exemplaryaralkoxycarbonyl group is benzyloxycarbonyl.

“Carbamoyl” refers to an amide group of the formula —C(═O)NH₂.“Alkylcarbamoyl” refers to a R′RN—C(═O)— group wherein one of R and R′is hydrogen and the other of R and R′ is alkyl and/or substituted alkylas previously described. “Dialkylcarbamoyl” refers to a R′RN—C(═O)—group wherein each of R and R′ is independently alkyl and/or substitutedalkyl as previously described.

The term carbonyldioxyl, as used herein, refers to a carbonate group ofthe formula —O—C(═O)—OR.

“Acyloxyl” refers to an acyl-O— group wherein acyl is as previouslydescribed.

The term “amino” refers to the —NH₂ group and also refers to a nitrogencontaining group as is known in the art derived from ammonia by thereplacement of one or more hydrogen radicals by organic radicals. Forexample, the terms “acylamino” and “alkylamino” refer to specificN-substituted organic radicals with acyl and alkyl substituent groupsrespectively.

An “aminoalkyl” as used herein refers to an amino group covalently boundto an alkylene linker. More particularly, the terms alkylamino,dialkylamino, and trialkylamino as used herein refer to one, two, orthree, respectively, alkyl groups, as previously defined, attached tothe parent molecular moiety through a nitrogen atom. The term alkylaminorefers to a group having the structure —NHR′ wherein R′ is an alkylgroup, as previously defined; whereas the term dialkylamino refers to agroup having the structure —NR′R″, wherein R′ and R″ are eachindependently selected from the group consisting of alkyl groups. Theterm trialkylamino refers to a group having the structure —NR′R″R′″,wherein R′, R″, and R″ are each independently selected from the groupconsisting of alkyl groups. Additionally, R′, R″, and/or R″ takentogether may optionally be —(CH₂)_(k)— where k is an integer from 2 to6. Examples include, but are not limited to, methylamino, dimethylamino,ethylamino, diethylamino, diethylaminocarbonyl, methylethylamino,isopropylamino, piperidino, trimethylamino, and propylamino.

The amino group is —NR′R″, wherein R′ and R″ are typically selected fromhydrogen, substituted or unsubstituted alkyl, substituted orunsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl,substituted or unsubstituted heterocycloalkyl, substituted orunsubstituted aryl, or substituted or unsubstituted heteroaryl.

The terms alkylthioether and thioalkoxyl refer to a saturated (i.e.,alkyl-S—) or unsaturated (i.e., alkenyl-S— and alkynyl-S—) groupattached to the parent molecular moiety through a sulfur atom. Examplesof thioalkoxyl moieties include, but are not limited to, methylthio,ethylthio, propylthio, isopropylthio, n-butylthio, and the like.

“Acylamino” refers to an acyl-NH-group wherein acyl is as previouslydescribed. “Aroylamino” refers to an aroyl-NH— group wherein aroyl is aspreviously described.

The term “carbonyl” refers to the —C(═O)— group, and can include analdehyde group represented by the general formula R—C(═O)H.

The term “carboxyl” refers to the —COOH group. Such groups also arereferred to herein as a “carboxylic acid” moiety.

The terms “halo,” “halide,” or “halogen” as used herein refer to fluoro,chloro, bromo, and iodo groups. Additionally, terms such as “haloalkyl,”are meant to include monohaloalkyl and polyhaloalkyl. For example, theterm “halo(C₁-C₄)alkyl” is mean to include, but not be limited to,trifluoromethyl, 2,2,2-trifluoroethyl, 4-chlorobutyl, 3-bromopropyl, andthe like.

The term “hydroxyl” refers to the —OH group.

The term “hydroxyalkyl” refers to an alkyl group substituted with an —OHgroup.

The term “mercapto” refers to the —SH group.

The term “oxo” as used herein means an oxygen atom that is double bondedto a carbon atom or to another element.

The term “nitro” refers to the —NO₂ group.

The term “thio” refers to a compound described previously herein whereina carbon or oxygen atom is replaced by a sulfur atom.

The term “sulfate” refers to the —SO₄ group.

The term thiohydroxyl or thiol, as used herein, refers to a group of theformula —SH.

More particularly, the term “sulfide” refers to compound having a groupof the formula —SR.

The term “sulfone” refers to compound having a sulfonyl group —S(O₂)R.

The term “sulfoxide” refers to a compound having a sulfinyl group —S(O)R

The term ureido refers to a urea group of the formula —NH—CO—NH₂.

Throughout the specification and claims, a given chemical formula orname shall encompass all tautomers, congeners, and optical- andstereoisomers, as well as racemic mixtures where such isomers andmixtures exist.

Certain compounds of the present disclosure may possess asymmetriccarbon atoms (optical or chiral centers) or double bonds; theenantiomers, racemates, diastereomers, tautomers, geometric isomers,stereoisometric forms that may be defined, in terms of absolutestereochemistry, as (R)- or (S)- or, as D- or L- for amino acids, andindividual isomers are encompassed within the scope of the presentdisclosure. The compounds of the present disclosure do not include thosewhich are known in art to be too unstable to synthesize and/or isolate.The present disclosure is meant to include compounds in racemic,scalemic, and optically pure forms. Optically active (R)- and (S)-, orD- and L-isomers may be prepared using chiral synthons or chiralreagents, or resolved using conventional techniques. When the compoundsdescribed herein contain olefenic bonds or other centers of geometricasymmetry, and unless specified otherwise, it is intended that thecompounds include both E and Z geometric isomers. Unless otherwisestated, structures depicted herein are also meant to include allstereochemical forms of the structure; i.e., the R and S configurationsfor each asymmetric center. Therefore, single stereochemical isomers aswell as enantiomeric and diastereomeric mixtures of the presentcompounds are within the scope of the disclosure.

It will be apparent to one skilled in the art that certain compounds ofthis disclosure may exist in tautomeric forms, all such tautomeric formsof the compounds being within the scope of the disclosure. The term“tautomer,” as used herein, refers to one of two or more structuralisomers which exist in equilibrium and which are readily converted fromone isomeric form to another.

Unless otherwise stated, structures depicted herein are also meant toinclude compounds which differ only in the presence of one or moreisotopically enriched atoms. For example, compounds having the presentstructures with the replacement of a hydrogen by a deuterium or tritium,or the replacement of a carbon by ¹³C- or ¹⁴C-enriched carbon are withinthe scope of this disclosure.

The compounds of the present disclosure may also contain unnaturalproportions of atomic isotopes at one or more of atoms that constitutesuch compounds. For example, the compounds may be radiolabeled withradioactive isotopes, such as for example iodine-125 (¹²⁵I) orastatine-211 (²¹¹At). All isotopic variations of the compounds of thepresent disclosure, whether radioactive or not, are encompassed withinthe scope of the present disclosure.

The compounds of the present disclosure may exist as salts. The presentdisclosure includes such salts. Examples of applicable salt formsinclude hydrochlorides, hydrobromides, sulfates, methanesulfonates,nitrates, maleates, acetates, citrates, fumarates, tartrates (e.g.(+)-tartrates, (−)-tartrates or mixtures thereof including racemicmixtures, succinates, benzoates and salts with amino acids such asglutamic acid. These salts may be prepared by methods known to thoseskilled in art. Also included are base addition salts such as sodium,potassium, calcium, ammonium, organic amino, or magnesium salt, or asimilar salt. When compounds of the present disclosure containrelatively basic functionalities, acid addition salts can be obtained bycontacting the neutral form of such compounds with a sufficient amountof the desired acid, either neat or in a suitable inert solvent or byion exchange. Examples of acceptable acid addition salts include thosederived from inorganic acids like hydrochloric, hydrobromic, nitric,carbonic, monohydrogencarbonic, phosphoric, monohydrogenphosphoric,dihydrogenphosphoric, sulfuric, monohydrogensulfuric, hydriodic, orphosphorous acids and the like, as well as the salts derived organicacids like acetic, propionic, isobutyric, maleic, malonic, benzoic,succinic, suberic, fumaric, lactic, mandelic, phthalic, benzenesulfonic,p-tolylsulfonic, citric, tartaric, methanesulfonic, and the like. Alsoincluded are salts of amino acids such as arginate and the like, andsalts of organic acids like glucuronic or galactunoric acids and thelike. Certain specific compounds of the present disclosure contain bothbasic and acidic functionalities that allow the compounds to beconverted into either base or acid addition salts.

The neutral forms of the compounds may be regenerated by contacting thesalt with a base or acid and isolating the parent compound in theconventional manner. The parent form of the compound differs from thevarious salt forms in certain physical properties, such as solubility inpolar solvents.

Certain compounds of the present disclosure can exist in unsolvatedforms as well as solvated forms, including hydrated forms. In general,the solvated forms are equivalent to unsolvated forms and areencompassed within the scope of the present disclosure. Certaincompounds of the present disclosure may exist in multiple crystalline oramorphous forms. In general, all physical forms are equivalent for theuses contemplated by the present disclosure and are intended to bewithin the scope of the present disclosure.

In addition to salt forms, the present disclosure provides compounds,which are in a prodrug form. Prodrugs of the compounds described hereinare those compounds that readily undergo chemical changes underphysiological conditions to provide the compounds of the presentdisclosure. Additionally, prodrugs can be converted to the compounds ofthe present disclosure by chemical or biochemical methods in an ex vivoenvironment. For example, prodrugs can be slowly converted to thecompounds of the present disclosure when placed in a transdermal patchreservoir with a suitable enzyme or chemical reagent.

The term “protecting group” refers to chemical moieties that block someor all reactive moieties of a compound and prevent such moieties fromparticipating in chemical reactions until the protective group isremoved, for example, those moieties listed and described in T. W.Greene, P. G. M. Wuts, Protective Groups in Organic Synthesis, 3rd ed.John Wiley & Sons (1999). It may be advantageous, where differentprotecting groups are employed, that each (different) protective groupbe removable by a different means. Protective groups that are cleavedunder totally disparate reaction conditions allow differential removalof such protecting groups. For example, protective groups can be removedby acid, base, and hydrogenolysis. Groups such as trityl,dimethoxytrityl, acetal and tert-butyldimethylsilyl are acid labile andmay be used to protect carboxy and hydroxy reactive moieties in thepresence of amino groups protected with Cbz groups, which are removableby hydrogenolysis, and Fmoc groups, which are base labile. Carboxylicacid and hydroxy reactive moieties may be blocked with base labilegroups such as, without limitation, methyl, ethyl, and acetyl in thepresence of amines blocked with acid labile groups such as tert-butylcarbamate or with carbamates that are both acid and base stable buthydrolytically removable.

Carboxylic acid and hydroxy reactive moieties may also be blocked withhydrolytically removable protective groups such as the benzyl group,while amine groups capable of hydrogen bonding with acids may be blockedwith base labile groups such as Fmoc. Carboxylic acid reactive moietiesmay be blocked with oxidatively-removable protective groups such as2,4-dimethoxybenzyl, while co-existing amino groups may be blocked withfluoride labile silyl carbamates.

Allyl blocking groups are useful in the presence of acid- andbase-protecting groups since the former are stable and can besubsequently removed by metal or pi-acid catalysts. For example, anallyl-blocked carboxylic acid can be deprotected with a palladium(O)—catalyzed reaction in the presence of acid labile t-butyl carbamate orbase-labile acetate amine protecting groups. Yet another form ofprotecting group is a resin to which a compound or intermediate may beattached. As long as the residue is attached to the resin, thatfunctional group is blocked and cannot react. Once released from theresin, the functional group is available to react.

Typical blocking/protecting groups include, but are not limited to thefollowing moieties:

Following long-standing patent law convention, the terms “a,” “an,” and“the” refer to “one or more” when used in this application, includingthe claims. Thus, for example, reference to “a subject” includes aplurality of subjects, unless the context clearly is to the contrary(e.g., a plurality of subjects), and so forth.

Throughout this specification and the claims, the terms “comprise,”“comprises,” and “comprising” are used in a non-exclusive sense, exceptwhere the context requires otherwise. Likewise, the term “include” andits grammatical variants are intended to be non-limiting, such thatrecitation of items in a list is not to the exclusion of other likeitems that can be substituted or added to the listed items.

For the purposes of this specification and appended claims, unlessotherwise indicated, all numbers expressing amounts, sizes, dimensions,proportions, shapes, formulations, parameters, percentages, quantities,characteristics, and other numerical values used in the specificationand claims, are to be understood as being modified in all instances bythe term “about” even though the term “about” may not expressly appearwith the value, amount or range. Accordingly, unless indicated to thecontrary, the numerical parameters set forth in the followingspecification and attached claims are not and need not be exact, but maybe approximate and/or larger or smaller as desired, reflectingtolerances, conversion factors, rounding off, measurement error and thelike, and other factors known to those of skill in the art depending onthe desired properties sought to be obtained by the presently disclosedsubject matter. For example, the term “about,” when referring to a valuecan be meant to encompass variations of, in some embodiments, ±100% insome embodiments ±50%, in some embodiments ±20%, in some embodiments±10%, in some embodiments ±5%, in some embodiments ±1%, in someembodiments ±0.5%, and in some embodiments ±0.1% from the specifiedamount, as such variations are appropriate to perform the disclosedmethods or employ the disclosed compositions.

Further, the term “about” when used in connection with one or morenumbers or numerical ranges, should be understood to refer to all suchnumbers, including all numbers in a range and modifies that range byextending the boundaries above and below the numerical values set forth.The recitation of numerical ranges by endpoints includes all numbers,e.g., whole integers, including fractions thereof, subsumed within thatrange (for example, the recitation of 1 to 5 includes 1, 2, 3, 4, and 5,as well as fractions thereof, e.g., 1.5, 2.25, 3.75, 4.1, and the like)and any range within that range.

In the examples below the following terms are intended to have thefollowing meaning: ACN: acetonitrile, DCM: Dichloromethane, DIPEA:N,N-Diisopropylethylamine, DMF: Dimethylformamide, HPLC: HighPerformance Liquid Chromatography, HRMS: High Resolution MassSpectrometry, LRMS: Low Resolution Mass Spectrometry, NCS:N-Chlorosuccinimide, NHS: N-Hydroxysuccinimide, NMR: nuclear magneticresonance, PMB: p-methoxybenzyl, RT: room temperature, TEA:Triethylamine, TFA: Trifluoroacetic acid, and TSTU:O—(N-Succinimidyl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate.

EXAMPLES

The following Examples have been included to provide guidance to one ofordinary skill in the art for practicing representative embodiments ofthe presently disclosed subject matter. In light of the presentdisclosure and the general level of skill in the art, those of skill canappreciate that the following Examples are intended to be exemplary onlyand that numerous changes, modifications, and alterations can beemployed without departing from the scope of the presently disclosedsubject matter. The synthetic descriptions and specific examples thatfollow are only intended for the purposes of illustration, and are notto be construed as limiting in any manner to make compounds of thedisclosure by other methods.

Example 1 Overview

In a representative example, 1-125 and At-211 labeled DOTA urea compoundVK-02-90 demonstrated high specific PSMA positive tumor uptake in mice.Renal uptake at 1 hour is high, but clears much more rapidly than theradiohalogenated ureas. In addition, radioactivity in the stomach isvery low, indicating that [²¹¹At]VK-02-90 is stable in-vivo unlike theprevious At-211 labeled ureas and almost all At-211 labeled smallmolecules. The lutetium complex of [¹²⁵I/²¹¹At]VK-02-90 exhibits muchlower initial uptake (1 h) in the kidneys and lacrimal glands comparedto its non-lutetium complex version.

In contrast, [¹²⁵I]VK03-03, which has the [¹²⁵I]iodophenyl moiety withinthe linking moiety, also has high and prolonged tumor uptake, but,unlike [¹²⁵I/²¹¹At]VK-02-90, radioactivity in the kidneys does not clearover time. [¹²⁵I] VK03-03 also has slower clearance from the lacrimalgland than [¹²⁵I/²¹¹At] VK-02-90. The lutetium complex of [¹²⁵I] VK03-03exhibits high and prolonged tumor uptake and does provide a modestclearance from the kidneys and lacrimal gland, but not to the extentseen with the lutetium complex of [¹²⁵I/²¹¹At] VK-02-90.

This comparison of VK-02-90 and VK03-03 illustrates how changing thestructure of the non-pharmacophore portion of the agent, in this casethe linker between the DOTA and lysine-glutamate urea, can affect theuptake and retention of the PSMA targeted tracer in normal tissues.

Co-injection of a small amount (0.25-0.5 nmole) of nonradioactive—ureaor—DOTA urea with [¹²¹I/²¹¹At] VK-02-90-Lu further reduces the uptake ofradioactivity in the kidneys and lacrimal glands, which are problematicnormal organs for radiopharmaceutical therapy. Taken together, 1-125 andAt-211 labeled DOTA urea compound VK-02-90-Lu administered with a smallamount of non-radioactive PSMA inhibitor produces a biodistribution inmice that is very favorable for PSMA targeted radiopharmaceuticaltherapy (RPT) and represents a major step forward in developing an RPTagent for prostate cancer. When translated to patients it may provide aneffective alpha radiotherapy for prostate cancer that eliminates orgreatly reduces the side effects of RPT with alpha emitters, namelyrenal toxicity and dry mouth.

Example 2 Synthesis of Non-Radioactive VK-02-90 and VK-02-90-Lu andRadiohalogenation Precursor VK-02-85

Provided immediately herein below is a synthesis scheme forrepresentative compounds VK-02-90, VK-02-90-Lu, and VK-02-85.

4-(Tributylstannyl)benzaldehyde (1) prepared as reported in Sessler, J.L., Wang, B., Harriman, A., Photoinduced energy transfer in associated,but noncovalently-linked photosynthetic model systems, JACS, 117,704-714 (1995).Di-tert-butyl(((S)-1-(tert-butoxy)-1-oxo-6-((4-(tributylstannyl)benzyl)amino)hexan-2-yl)carbamoyl)-L-glutamate(VK02-71): 4-(Tributylstannyl)benzaldehyde solution (0.500 g, 1.26 mmol,in 5 mL MeOH) was added dropwise to a stirred solution of urea (2)(0.614 g, 1.26 mmol) in MeOH (5 mL) at 0-5° C. under an inertatmosphere. The reaction mixture was stirred at RT for 1 h and thentreated with sodium cyanoborohydride (0.318 g, 5.05 mmol). The mixturewas stirred overnight at RT and concentrated in vacuum. Purification byflash column chromatography eluting with 40-50% EtOAc/Hexanes provided0.537 g (49%) of oily material. ¹HNMR (500 MHz, CDCl₃) δ ppm 7.48 (d,J=10.0 Hz, 2H), 7.36 (d, J=5.0 Hz, 2H), 5.92 (m, 1H), 5.73 (m, 1H),4.26-4.23 (m, 1H), 4.07-4.00 (m, 2H), 2.87-2.84 (m, 2H), 2.29 (t, J=5.0Hz, 2H), 1.91-1.87 (m, 1H), 1.80-1.78 (m, 1H), 1.72-1.70 (m, 2H),1.59-1.55 (m, 1H), 1.53-1.49 (m, 5H), 1.45-1.41 (m, 27H), 1.34-1.26 (m,7H), 1.25-1.22 (m, 3H), 1.05-1.02 (m, 6H), 0.86 (t, J=5.0 Hz, 9H); ¹³CNMR (125 MHz, CDCl₃) δ ppm 173.4, 172.5, 172.4, 172.2, 157.8, 143.9,137.2, 137.0, 129.2, 82.6, 81.8, 80.6, 53.8, 53.5, 53.1, 51.9, 46.9,31.7, 31.6, 29.7, 29.0, 28.1, 28.0, 27.3, 26.9, 26.1, 22.9, 13.7, 9.6.ESMS m/z: 868.4 (M+H)⁺.Tri-tert-butyl(15S,19S)-1-(9H-fluoren-9-yl)-3,9,17-trioxo-10-(4-(tributylstannyl)benzyl)-2-oxa-4,10,16,18-tetraazahenicosane-15,19,21-tricarboxylate(VK02-73): A mixture of 5-(Fmoc-amino)valeric acid (0.019 g, 0.06 mmol),TSTU (0.017 g, 0.06 mmol) and DIPEA (0.015 g, 0.11 mmol) were stirred inDMF (1 mL) at RT for 1 h. Amine (VK02-71, 0.05 g, 0.06 mmol) was addeddropwise after dilution with DMF (1 mL). The reaction mixture wasstirred for 4 h, concentrated and purified by flash columnchromatography eluting with 40-50% EtOAc/Hexanes provided 0.537 g (47%)of oily material. ¹H NMR (500 MHz, CDCl₃) δ ppm 7.76 (d, J=10.0 Hz, 3H),7.60 (d, J=5.0 Hz, 3H), 7.40 (m, 4H), 7.31 (m, 4H), 4.99 (bs, 1H), 4.40(m, 3H), 4.21 (m, 1H), 3.23 (q, J=5.0 Hz, 3H), 2.83 (m, 5H), 2.66-2.63(m, 2H), 2.36-2.29 (m, 1H), 1.89-1.81 (m, 1H), 1.80-1.75 (m, 4H),1.65-1.62 (m, 4H), 1.55-1.52 (m, 4H), 1.45-1.42 (m, 14H), 1.36-1.23 (m,20H), 1.11-1.01 (m, 4H), 0.97 (d, J=5.0 Hz, 1H), 0.90-0.86 (m, 11H); ¹³CNMR (125 MHz, CDCl₃) δ ppm 169.2, 168.4, 156.5, 144.0, 141.3, 136.9,127.7, 127.0, 125.1, 119.9, 66.5, 47.3, 40.3, 34.7, 31.6, 30.9, 29.7,29.1, 28.1, 28.0, 27.4, 27.3, 25.6, 25.3, 22.7, 21.8, 18.8, 14.2, 13.7,11.5, 9.6. ESMS m/z: 1208 (M−H+Na)⁺.Di-tert-butyl(((S)-6-(5-amino-N-(4-(tributylstannyl)benzyl)pentanamido)-1-(tert-butoxy)-1-oxohexan-2-yl)carbamoyl)-L-glutamate(VK02-86): A solution of 20% piperidine/DMF (2.5 mL) was added toVK02-73 (0.317 g, 0.27 mmol) and stirred at RT for 2.5 h. The reactionmixture was concentrated and purified by flash chromatography elutingwith 10% MeOH/CH₂Cl₂/NH₄OH, lyophilized to provide 0.190 g (74%) of oilyproduct. ¹HNMR (500 MHz, CDCl₃) δ ppm 7.44 (d, J=5.0 Hz, 1H), 7.38 (d,J=5.0 Hz, 1H), 7.14 (d, J=5.0 Hz, 1H), 7.08 (d, J=5.0 Hz, 1H), 6.25 (m,1H), 6.14-6.11 (m, 1H), 4.61-4.49 (m, 1H), 4.48-4.44 (m, 1H), 4.32-4.27(m, 2H), 3.54-3.50 (m, 1H), 3.41 (m, 1H), 3.29-3.18 (m, 2H), 3.06-3.03(m, 2H), 2.68 (m, 1H), 2.49-2.36 (m, 2H), 2.35-2.30 (m, 3H), 2.06-2.04(m, 1H), 1.87-1.73 (m, 8H), 1.60-1.49 (m, 7H), 1.43-1.42 (m, 27H),1.35-1.27 (m, 8H), 1.05-1.00 (m, 6H), 0.87 (t, J=10.0 Hz, 9H); ¹³C NMR(125 MHz, CDCl₃) δ ppm 173.9, 173.0, 172.8, 172.7, 157.5, 157.3, 141.3,140.7, 137.0, 136.7, 136.2, 127.5, 125.8, 81.9, 81.8, 81.4, 80.6, 53.6,52.9, 50.6, 47.8, 46.6, 45.1, 40.5, 32.7, 31.8, 29.7, 29.2, 29.1, 28.1,27.4, 27.2, 26.9, 22.5, 21.9, 13.7, 9.6. ESMS m/z: 967.3 (M+H)⁺.Tri-tert-butyl(14S,18S)-2,8,16-trioxo-9-(4-(tributylstannyl)benzyl)-1-(4,7,10-tris(2-(tert-butoxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)-3,9,15,17-tetraazaicosane-14,18,20-tricarboxylate(VK02-85): A reaction mixture of DOTA-NHS-ester (0.028 g, 0.03 mmol),VK02-86 (0.030 g, 0.03 mmol) and DIPEA (0.040 g, 0.31 mmol) were stirredin DMSO (1 mL) at RT for 3 h. The reaction mixture was concentrated andpurified by flash chromatography eluting with 1.5% MeOH/CH₂C₁₂ toprovide 0.024 g (51%) of oily product. ¹H NMR (500 MHz, CDCl₃) δ ppm7.40 (d, J=5.0 Hz, 1H), 7.35 (d, J=10.0 Hz, 1H), 7.11 (d, J=10.0 Hz,1H), 7.07 (d, J=10.0 Hz, 1H), 6.56-6.52 (m, 1H), 6.15 (bs, 1H), 5.59 (d,J=10.0 Hz, 1H), 5.42 (d, J=5.0 Hz, 1H), 4.50 (d, J=10.0 Hz, 2H),4.30-4.21 (m, 2H), 3.72-3.64 (m, 1H), 3.35-3.30 (m, 3H), 3.22-3.12 (m,5H), 2.84 (m, 6H), 2.39 (m, 2H), 2.33-2.25 (m, 6H), 2.04-2.01 (m, 3H),1.85 (m, 1H), 1.69-1.58 (m, 4H), 1.57-1.47 (m, 10H), 1.44-1.38 (m, 59H),1.34-1.26 (m, 9H), 1.03-0.98 (m, 6H), 0.85 (t, J=10.0 Hz, 9H); ¹³C NMR(125 MHz, CDCl₃) δ ppm 173.5, 173.1, 172.9, 172.5, 172.4, 172.1, 171.4,171.3, 169.7, 157.1, 157.0, 141.1, 140.5, 137.5, 136.9, 136.6, 136.5,127.4, 125.8, 82.2, 81.9, 81.8, 81.7, 81.6, 56.0, 55.7, 53.2, 53.1,52.9, 50.9, 48.1, 46.9, 45.5, 39.2, 39.1, 32.8, 32.6, 31.8, 31.7, 30.9,29.1, 28.1, 28.0, 27.9, 27.8, 27.4, 26.6, 25.6, 22.6, 22.5, 22.4, 13.7,9.6. ESMS m/z: 1518.8 (M−H)⁺.Tri-tert-butyl(14S,18S)-9-(4-iodobenzyl)-2,8,16-trioxo-1-(4,7,10-tris(2-(tert-butoxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)-3,9,15,17-tetraazaicosane-14,18,20-tricarboxylate(VK02-89):Iodine (0.012 g) was added to a solution of VK02-85 (0.049 g, 0.032mmol) in CH₂Cl₂ (2 mL) and stirred for 2h at RT. The reaction mixturewas washed with 10% aqueous Na₂S₂O₅ solution, dried, concentrated andpurified by flash chromatography eluting with 1.5% MeOH/CH₂Cl₂ toprovide 0.029 g (66%) of yellowish oily product. ¹H NMR (500 MHz,DMSO-d6) δ ppm 7.65 (d, J=10.0 Hz, 1H), 7.60 (d, J=10.0 Hz, 1H), 6.97(d, J=10.0 Hz, 1H), 6.92 (d, J=5.0 Hz, 1H), 6.54 (m, 1H), 5.22 (d, J=5.0Hz, 1H), 4.50 (m, 2H), 4.32-4.25 (m, 2H), 3.47 (m, 1H), 3.33-3.30 (m,3H), 3.22-3.15 (m, 4H), 2.86 (m, 6H), 2.65-2.52 (m, 3H), 2.42-2.40 (m,2H), 2.33-2.24 (m, 5H), 2.07-2.04 (m, 3H), 1.86 (m, 3H), 1.70-1.56 (m,10H), 1.46-1.42 (m, 48H), 1.37-1.20 (m, 8H), 0.92 (t, J=5.0 Hz, 3H); ¹³CNMR (125 MHz, DMSO-d6) δ ppm 173.6, 173.1, 172.6, 172.5, 172.4, 172.3,171.9, 171.4, 157.1, 137.9, 137.6, 131.0, 130.0, 128.3, 92.5, 81.9,81.8, 81.7, 81.6, 56.0, 55.7, 53.5, 53.1, 52.9, 50.6, 47.9, 47.3, 45.8,39.1, 32.8, 32.5, 32.3, 31.6, 30.9, 28.8, 28.6, 28.2, 28.11, 28.0, 27.9,26.8, 22.5, 22.4, 13.6. ESMS m/z: 702.4 (M/2+Na)⁺.(14S,18S)-9-(4-Iodobenzyl)-2,8,16-trioxo-1-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)-3,9,15,17-tetraazaicosane-14,18,20-tricarboxylicacid (VK02-90): A cold solution of 50% TFA/CH₂Cl₂ (2 mL) was added toVK02-89 (0.064 g, 0.05 mmol) and stirred at RT for 2 h. The reactionmixture was concentrated and purified by C-18 column chromatographyeluting with 40-50% acetonitrile/water, lyophilized to provide 0.030 g(62%) of white solid product. ¹H NMR (500 MHz, DMSO-d6) δ ppm 12.65 (bs,1H), 8.46 (s, 1H), 7.69 (d, J=3.0 Hz, 2H), 7.01 (s, 2H), 6.33 (s, 2H),4.47 (d, J=4.0 Hz, 2H), 4.08 (s, 5H), 3.88 (s, 3H), 3.09 (m, 15H), 2.37(s, 2H), 2.24 (s, 3H), 1.91 (s, 1H), 1.71-1.62 (m, 2H), 1.44 (m, 9H),1.23 (s, 2H); ¹³C NMR (125 MHz, DMSO-d6) δ ppm 174.5, 174.4, 174.1,173.7, 171.9, 158.0, 157.3, 138.4, 137.4, 137.1, 129.9, 128.8, 118.2,115.8, 92.9, 92.7, 54.7, 54.0, 52.7, 52.2, 52.1, 51.7, 50.6, 49.6, 48.2,47.1, 46.7, 31.8, 31.4, 29.9, 28.4, 27.8, 27.5, 26.7, 22.5, 22.3, 22.2.ESMS m/z: 1021.2 (M+H)⁺.¹⁷⁵Lutetium (III)(14S,18S)-9-(4-Iodobenzyl)-2,8,16-trioxo-1-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)-3,9,15,17-tetraazaicosane-14,18,20-tricarboxylicacid ([¹⁷⁵Lu]WK02-90): 7.92 mg (0.008 VK02-90 was dissolved in 25 μL ofDMSO and diluted with 0.2 M NH₄OAc (1 mL). A solution of 2.7 mg (0.008μmol) of Lu(NO₃)₃.xH₂O (dissolved in 5404 of 0.1 M HCl) was added andheated at 70-80° C. for 1 h on water bath. The product was purified byHPLC using Phenomenex, Luna 10×250 mm, 10μ gradient 20/80/0.1 to90/10/0.1 MeCN/H₂O/TFA, 0-40 min, flow 15 mL/min. Product eluted at 4.8min. HRESI-MS: calcd. for C₄₀H₅₈ILuN₈O₁₅ 1193.2547 [MH]⁺, found:1193.2535.

Example 3 Radiochemistry

3.1 Multi-Step Synthesis with Isolation and Purification at Each Step.

3.1.1 Synthesis of [¹²⁵I]VK-02-90.

200 μg of VK-02-85 was dissolved in 100 μL methanol in a borosilicatescrew capped vial. To this is added 2 μL glacial acetic acid and 7.2 mCiof a solution of Na¹²⁵I (Perkin Elmer), followed by 25 μL of a solutionconsisting of 1 mg N-chlorosuccinimide dissolved in 1 mL methanol. Vialwas capped, shaken, and allowed to stand 20 min at room temperature. Thereaction was concentrated to almost dryness under a stream of nitrogenwith gentle heating. To this is added 200 μL trifluoroacetic acid andthe vial was heated at 70° C. for 45 min, then concentrated undernitrogen, redissolved in 2 mL 20% acetonitrile in water, and purified byradio-HPLC (250×10 mm, 10 micron, Phenomenex Luna C18 column.Water/acetonitrile (both containing 0.1% TFA) Gradient elution. 15%acetonitrile to 50% acetonitrile over 30 min, flow 4 mL/m.[¹²⁵I]VK-02-90 (3.6 mCi) eluted @ 17 min. [¹²⁵I]VK-02-90 in the HPLCmobile phase was diluted to 20 mL with water and loaded onto a WatersOasis HLB Sep-Pak, washed with 5 mL water, blown dry was a stream ofnitrogen and eluted with 2 mL ethanol. This was concentrated under astream of nitrogen.

3.1.2 Synthesis of [¹²⁵I]VK-02-90-Lu

The ethanol solution of [¹²⁵I]VK-02-90 was concentrated to almostdryness under a stream of nitrogen. To this is added 150 μL 0.1M NaOAc(pH 4.5), and 25 μL 5 mM Lu(NO₃)₃ in 0.1M HCl and mixed by micropipette.This solution was heated at 70° C. for 20 min, quenched with 100 μL 5 mMEDTA, diluted with 600 μL water and purified by radio-HPLC (250×10 mm,10 micron, Phenomenex Luna C18 column. Water/acetonitrile (bothcontaining 0.1% TFA) Gradient elution. 15% acetonitrile to 40%acetonitrile over 30 min, flow 4 mL/m. [¹²⁵I]VK-02-90-Lu (2.8 mCi)eluted at 21.5 min. Under these conditions, [¹²⁵I]VK-02-90 eluted at20.5 min. Specific Activity of [¹²⁵I]VK-02-90-Lu was 2000 C₁/mmole.[¹²⁵I]VK-02-90-Lu in the HPLC mobile phase was diluted to 20 mL withwater and loaded onto a Waters Oasis HLB Sep-Pak, washed with 5 mLwater, blown dry with a stream of nitrogen and eluted with 2 mL ethanol.This was concentrated under a stream of nitrogen.

3.1.3 Synthesis of [²¹¹At]VK-02-90

680 μg of VK-02-85 was dissolved in 190 μL of a solution consisting of0.2 mg N-chlorosuccinimide/mL methanol and ²¹¹At (12.0 mCi) in aborosilicate screw capped vial. To this is added 2 μL glacial aceticacid. Vial was capped, shaken, and allow to stand 20 min at roomtemperature. The reaction was concentrated to almost dryness under astream of nitrogen with gentle heating. To this is added 200 μLtrifluoroacetic acid and the vial was heated at 70° C. for 45 min, thenconcentrated under nitrogen, redissolved in 2 mL 20% acetonitrile inwater, and purified by radio-HPLC (250×10 mm, 10 micron, Phenomenex LunaC18 column. Water/acetonitrile (both containing 0.1% TFA) Gradientelution. 15% acetonitrile to 40% acetonitrile over 30 min, flow 4 mL/m.[²¹¹At]VK-02-90 (1.5 mCi) eluted at 20 min. [²¹¹At]VK-02-90 in the HPLCmobile phase was diluted to 20 mL with water and loaded onto a WatersOasis HLB Sep-Pak, washed with 5 mL water, blown dry with a stream ofnitrogen and eluted with 2 mL ethanol. This was concentrated under astream of nitrogen.

3.1.4 Synthesis of [²¹¹At] VK-02-90-Lu

The ethanol solution of [²¹¹At]VK-02-90 was concentrated to almostdryness under a stream of nitrogen. To this is added 150 μL 0.1M NaOAc(pH 4.5), and 25 μL 5 mM Lu(NO₃)₃ in 0.1M HCl and mixed by micropipette.This solution was heated at 70° C. for 20 min, quenched with 100 μL 5 mMEDTA, diluted with 600 μL water and purified by radio-HPLC (250×10 mm,10 micron, Phenomenex Luna C18 column. Water/acetonitrile (bothcontaining 0.1% TFA) Gradient elution. 15% acetonitrile to 40%acetonitrile over 30 min, flow 4 mL/m. [²¹¹At]VK-02-90-Lu (0.6 mCi)eluted at 19 min. [²¹¹At]VK-02-90-Lu in the HPLC mobile phase wasdiluted to 20 mL with water and loaded onto a Waters Oasis HLB Sep-Pak,washed with 5 mL water, blown dry with a stream of nitrogen and elutedwith 2 mL ethanol. This was concentrated under a stream of nitrogen.

3.2 Multi-Step One Pot Synthesis

3.2.1 Multi-Step One Pot Synthesis of [¹²⁵I]VK-02-90-Lu

100-160 μg of VK-02-85 was placed in a borosilicate screw capped vial.To this is added 200 μL of a solution consisting of 0.2 mgN-chlorosuccinimide/mL methanol. To this was added 1.3-1.7 mCi Na¹²⁵I(Perkin Elmer) dissolved in 20 μL water. Finally, 8 μL glacial aceticacid was added and the vial capped, shaken and allowed to stand 10 minat room temperature. The reaction was concentrated to almost drynessunder a stream of nitrogen on a 57-60° C. heating bath. To this is added200 μL 95/5 trifluoroacetic acid/water and the vial was heated at 60° C.for 30 min, then concentrated under nitrogen on a 57-60° C. heatingbath. To this is added 200 μL 0.1M NaOAc (pH 4.5), and 30 μL 5 mMLu(NO₃)₃ in 0.1M HCl and mixed by micropipette. This solution was heatedat 60° C. for 20 min, quenched with 100 μL 5 mM EDTA, diluted with 600μL water and purified by radio-HPLC (250×4.6 mm, 10 micron, PhenomenexLuna C18 column. Water/acetonitrile (both containing 0.1% TFA) Gradientelution. 15% acetonitrile to 40% acetonitrile over 30 min, flow 1 mL/m.[¹²⁵I]VK-02-90-Lu elutes at 22.5 min. [¹²⁵I]VK-02-90-Lu in the HPLCmobile phase was diluted to 20 mL with water and loaded onto a WatersOasis HLB light Sep-Pak, washed with 5 mL water, blown dry with a streamof nitrogen, and eluted with 0.5 mL ethanol.

3.2.2 Multi-Step One Pot Synthesis of [²¹¹At]VK-02-90-Lu

200 μg of VK-02-85 was placed in a borosilicate screw capped vial. Tothis was added ²¹¹At in 200 μL of a solution consisting of 0.2 mgN-chlorosuccinimide/mL methanol. To this was added 8 μL glacial aceticacid and the vial capped, shaken and allowed to stand 10 min at roomtemperature. The reaction was concentrated to dryness under a stream ofnitrogen on a 60° C. heating bath. To this is added 200 μL 95/5trifluoroacetic acid/water and the vial was heated at 60° C. for 30 min,then concentrated under nitrogen on a 60° C. heating bath. To this isadded 200 μL 0.1M NaOAc (pH 4.5), and 30 μL 5 mM Lu(NO₃)₃ in 0.1M HCland mixed by micropipette. This solution was heated at 60° C. for 20min, quenched with 100 μL 5 mM EDTA, diluted with 600 μL water andpurified by radio-HPLC (250×4.6 mm, 10 micron, XTerra C18 column.Water/acetonitrile (both containing 0.1% TFA) Gradient elution. 15%acetonitrile to 40% acetonitrile over 30 min, flow 1 mL/m.[²¹¹At]VK-02-90-Lu elutes at 16.5-18 min. [²¹¹At]VK-02-90-Lu in the HPLCmobile phase was diluted to 20 mL with water and loaded onto a WatersOasis HLB light Sep-Pak, washed with 5 mL water, blown dry with a streamof nitrogen, and eluted with 0.5 mL ethanol.

TABLE 1 Radiochemical Yields Labeling Product and Non-decay method Ageof At-211 corrected yield A NA [¹²⁵I]VK-02-90-Lu 39% B NA[¹²⁵I]VK-02-90-Lu 50-63% A Fresh [²¹¹At]VK-02-90-Lu 9% A 18 hourpost-production [²¹¹At]VK-02-90-Lu 5% B Fresh [²¹¹At]VK-02-90-Lu 23% B18 hour post-production [²¹¹At]VK-02-90-Lu 15% Method A: HPLCpurification and isolation of both [¹²⁵I/²¹¹At]WK-02-90 and[125I/211At]VK-02-90-Lu Method B: Multi-step-single pot, HPLCpurification of [¹²⁵I/²¹¹At]VK-02-90-Lu only.

Example 4 Biodistribution Studies [¹²⁵I]VK-02-90-Lu and[²¹¹At]VK-02-90-Lu

Referring now to Table 2, comparative biodistribution of [¹²⁵I]VK-02-90and [¹²⁵I]VK-02-90-Lu demonstrates the faster clearance of[¹²⁵I]VK-02-90-Lu from the spleen, salivary glands, lacrimal glands andkidneys.

TABLE 2 Biodistribution (% injected dose/g) of I-125 Labeled PSMAinhibitors in 6-8 week old athymic mice (25 g) bearing both PSMA+PC3-PIP and PSMA− PC3-flu flank xenografts without cold blocking agent.[¹²⁵I]VK-02-90 [¹²⁵I]VK-02-90-Lu Organs 1 H 4 H 24 H 1 H 4 H 24 H blood1.1 ± 0.3  0.2 ± 0.03 0.02 ± 0.01 1.2 ± 0.4 0.06 ± 0.06  0.1 ± 0.01stomach 1.1 ± 0.3 0.4 ± 0.2 0.05 ± 0.03 0.7 ± 0.4 0.1 ± 0.1 0.04 ± 0.01spleen 40.2 ± 16.4 4.7 ± 1.2 0.7 ± 0.4 7.4 ± 2.6 0.6 ± 0.2  0.1 ± 0.06thyroid NC NC NC NC NC NC salivary 5.1 ± 3.4 0.7 ± 0.2 0.3 ± 0.3 1.0 ±0.3  0.1 ± 0.05 0.03 ± 0.01 glands Lacrimal 17.4 ± 6.0   1.9 ± 0.45 0.5± 0.2 4.1 ± 1.3 0.3 ± 0.1 0.06 ± 0.03 glands kidneys 194 ± 25  162 ± 36 30.6 ± 14.0 180 ± 36  18.2 ± 4.9  3.3 ± 1.1 Pip (tumor) 58 ± 14 38 ± 1351 ± 7   51 ± 8.5 27.8 ± 17   24.0 ± 6.2  Flu (tumor) 1.4 ± 0.6  0.3 ±0.06 0.04 ± 0.02 0.9 ± 0.3 0.3 ± 0.5 0.03 ± 0.01 NC - Not Collected

Tables 3, 4, and 5 are comparisons of cold blocking agents YC-I-27 andVK-02-90 at doses of 0.5, 1.0, and 5 nmoles on the biodistribution (%injected dose/g) of [¹²⁵I]VK-02-90-Lu in 6-8 week old athymic micebearing both PSMA+PC3-PIP and PSMA-PC3-flu flank xenografts at 1, 4, and24 hours, respectively.

TABLE 3 1-hour Biodistribution Blocker YC-I-27 YC-I-27 YC-I-27 VK-02-90VK-02-90 VK-02-90 Organ None 0.5 nmole 1.0 nmole 5 nmole 0.5 nmole 1.0nmole 5.0 nmole Blood 1.1 ± 0.1 1.1 ± 0.1 1.0 ± 0.1 1.1 ± 0.2 0.4 ± 0.10.4 ± 0.1 0.5 ± 0.1 Stomach 1.7 ± 0.3 1.8 ± 0.2 1.8 ± 0.3 2.2 ± 0.7 0.2± 0.1  0.2 ± 0.04  0.2 ± 0.06 Spleen 4.3 ± 0.9 0.8 ± 0.2 0.6 ± 0.1 0.7 ±0.1 1.1 ± 0.4 1.1 ± 0.4 0.7 ± 0.2 Salivary 2.3 ± 0.5 3.2 ± 0.7 2.9 ± 0.45.1 ± 1.7  0.2 ± 0.03  0.2 ± 0.06 0.3 ± 0.1 glands Lacrimal 2.1 ± 0.90.5 ± 0.1  0.6 ± 0.05 1.1 ± 0.6 0.4 ± 0.1 0.4 ± 0.1  0.4 ± 0.03 GlandsKidneys 129 ± 15  4.2 ± 1.3 2.4 ± 0.8 2.3 ± 0.7 9.9 ± 2.5 6.5 ± 0.9 4.2± 0.5 PIP tumor 26.0 ± 3.0  41.8 ± 4.2  29.1 ± 2.4  20.1 ± 2.8  36.7 ±6.8  35.1 ± 9.0  23.5 ± 4.3  Flu tumor 1.0 ± 0.2 1.0 ± 0.3 0.8 ± 0.2 0.8± 0.2 0.6 ± 0.3 0.5 ± 0.1 0.9 ± 0.3

TABLE 4 4-hr Biodistribution Blocker YC-I-27 YC-I-27 YC-I-27 VK-02-90VK-02-90 VK02-90 Organ None 0.5 nmole 1.0 nmole 5 nmole 0.5 nmole 1.0nmole 5.0 nmole Blood 0.3 ± 0.2  0.4 ± 0.06  0.4 ± 0.05 0.4 ± 0.1 0.02 ±0.01  0.2 ± 0.01 0 Stomach 0.8 ± 0.5 1.3 ± 0.2 1.2 ± 0.2 1.6 ± 0.4 0.06± 0.01  0.1 ± 0.03  0.1 ± 0.04 Spleen 0.6 ± 0.2 0.25 ± 0.07  0.2 ± 0.04 0.3 ± 0.06 0.2 ± 0.1 0.2 ± 0.1 0.15 ± 0.08 Salivary 1.8 ± 0.2 3.3 ± 0.83.2 ± 0.7 5.0 ± 1.4 0.08 ± 0.04  0.1 ± 0.02 0.05 ± 0.02 glands Lacrimal0.4 ± 0.2  0.2 ± 0.02  0.2 ± 0.03 0.5 ± 0.5  0.1 ± 0.03  0.1 ± 0.05 0.1± 0.1 glands Kidneys 9.5 ± 2.5 0.9 ± 0.1  0.6 ± 0.03 0.7 ± 0.1 2.1 ± 0.71.4 ± 0.4 0.9 ± 0.3 PIP tumor 27.4 ± 7.5  24.0 ± 3.2  23.8 ± 1.1  14.3 ±5.0  24.8 ± 2.0  27.1 ± 3.6  18.8 ± 2.0  Flu tumor 0.25 ± 0.1  0.3 ± 0.10.3 ± 0.1 0.3 ± 0.1  0.1 ± 0.02  0.1 ± 0.03  0.1 ± 0.01

TABLE 5 24-hour Biodistribution Blocker YC-I-27 YC-I-27 YC-I-27 VK-02-90VK-02-90 VK-02-90 Organ None 0.5 nmole 1.0 nmole 5 nmole 0.5 nmole 1.0nmole 5.0 nmole Blood 0 0.03 ± 0.03 0.02 ± 0.01 0.02 ± 0.01  0.1 ± 0.010 0 Stomach  0.1 ± 0.04 0.1 ± 0.1 0.08 ± 0.03 0.07 ± 0.1  0.04 ± 0.040.03 ± 0.02 0.04 ± 0.03 Spleen  0.1 ± 0.05 0.02 ± 0.02 0.04 ± 0.02 0.01± 0.03 0.04 ± 0.01 0 0.01 ± 0.03 Salivary  0.2 ± 0.08 0.6 ± 0.5 0.4 ±0.2 0.4 ± 0.1 0.02 ± 0.01 0 0.01 ± 0.01 glands Lacrimal 0.05 ± 0.04 0.03± 0.04 0.02 ± 0.02 0.01 ± 0.02 0.03 ± 0.02 0 0.01 ± 0.03 glands Kidneys1.3 ± 0.7  0.1 ± 0.05   0.08 ± 0.0.05 0.05 ± 0.02 0.5 ± 0.2 0.4 ± 0.10.2 ± 0.2 PIP tumor 18.0 ± 6.0  13.4 ± 3.8  12.6 ± 3.1  6.6 ± 3.2 16.3 ±4.2  18.3 ± 3.7  10.6 ± 3.2  Flu tumor 0.05 ± 0.01 0.04 ± 0.02 0.03 ±0.01 0.03 ± 0.01 0.04 ± 0.01 0.03 ± 0.01 0.02 ± 0.01

Referring now to Table 6, Table 7, and Table 8 are the biodistributionsof At-211 labeled compounds showing the lower kidney and stomach uptakeof [²¹¹At]VK-02-90-Lu compared to other At-211 labeled PSMA inhibitorsreported in International PCT Patent Application Publication No.WO2017070482 A2, to Pomper et al., published Apr. 27, 2017, at 1 hour,2-4 hours, and 21-24 hours, respectively.

TABLE 6 1 Hour Biodistribution (% injected dose/g) of At-211 LabeledPSMA inhibitors in 6-8 week old athymic mice (25 g) bearing both PSMA+PC3-PIP and PSMA− PC3-flu flank xenografts with and without coldblocking agent. Agent YC-IV- PSMA- PSMA- [Lu]VK- [Lu]VK- [Lu]VK- YC-I-2711 620 904 HS-549 02-90 02-90 + 02-90 (no (no (no (no (no (no (0.25nmole (0.5 nmole Organ blocker) blocker) blocker) blocker) blocker)blocker) YC-I-27) YC-I-27) blood 1.7 ± 0.3 1.8 ± 1.6 1.0 ± 0.2 0.6 ± 0.35.5 ± 0.8 0.8 ± 0.2  0.6 ± 0.04 0.5 ± 0.1 stomach 10.1 ± 1.7  5.4 ± 0.62.0 ± 0.4 1.6 ± 0.6 7.1 ± 2.2 0.4 ± 0.1 0.4 ± 0.2 0.4 ± 0.2 spleen 29 ±10 8.9 ± 1.3 17.1 ± 3.7  9.5 ± 2.8 8.8 ± 2.1 2.5 ± 0.9 0.5 ± 0.4 0.3 ±0.4 thyroid 3.7 ± 1.1 1.6 ± 0.2 0.8 ± 0.2 0.5 ± 0.2 3.2 ± 0.6 NC NC NCsalivary NC NC NC NC NC 0.5 ± 0.2  0.4 ± 0.15  0.4 ± 0.15 gland lacrimalNC NC NC NC NC 0.8 ± 0.9 0.1 ± 0.4 0 gland kidney 71 ± 12 135 ± 19  103± 24  87 ± 15 46.7 ± 8.2  90 ± 43 5.0 ± 1.6 2.2 ± 0.6 PIP (tumor) 17.9 ±3.0  13.8 ± 5.1  16.5 ± 4.8  22.7 ± 5.4  43.2 ± 9.8  30.6 ± 4.8  34.2 ±7.8  25.4 ± 4.4  Flu (tumor) 2.2 ± 0.4 1.4 ± 0.2 1.1 ± 0.2 0.8 ± 0.3 3.5± 0.5 0.4 ± 0.2 0.4 ± 0.1 0.4 ± 0.1

TABLE 7 2-4 Hour Biodistribution (% injected dose/g) of At-211 LabeledPSMA inhibitors in 6-8 week old athymic mice (25 g) beanng both PSMA+PC3-PIP and PSMA− PC3-flu flank xenografts with and without coldblocking agent. Agent YC-I- YC-IV- PSMA- PSMA- [Lu]VK- [Lu]VK- [Lu]VK-27^(a) 11^(a) 620^(a) 904^(b) HS-549^(b) 02-90^(a) 02-90^(a) + 02-90^(a)(no (no (no (no (no (no (0.25 nmole (0.5 nmole Organ blocker) blocker)blocker) blocker) blocker) blocker) YC-I-27) YC-I-27) Blood 1.0 ± 0.10.6 ± 0.1 0.3 ± 0.1  0.4 ± 0.03 2.9 ± 0.4  0.1 ± 0.03 0.2 ± 0.1 0.2 ±0.1 Stomach 13.3 ± 3.1  8.0 ± 2.3 2.9 ± 0.6 2.9 ± 0.7 14.3 ± 3.2  0.3 ±0.2 0.5 ± 0.3  0.4 ± 0.05 Spleen 20.3 ± 3.6  5.8 ± 1.9 3.6 ± 2.4 4.3 ±2.0 6.1 ± 1.6 0 0.1 ± 0.5 0.8 ± 0.5 Thyroid 3.8 ± 1.2 2.0 ± 0.3 0.8 ±0.2 1.0 ± 0.3 4.1 ± 2.0 NC NC NC Salivary NC NC NC NC NC 0.2 ± 0.1 0.2 ±0.1 0.3 ± 0.2 gland Lacrimal NC NC NC NC NC 0.3 ± 1.1 0.4 ± 0.4 0 glandKidney 60 ± 12 70 ± 43 78 ± 39 88 ± 11 40 ± 15 2.1 ± 0.6 1.4 ± 0.3 0.7 ±0.1 PIP (tumor) 18.3 ± 2.9  13.3 ± 4.2  18.3 ± 4.3  21.1 ± 6.2   42 ±7.2 17.1 ± 5.2  27.8 ± 8.7  18.7 ± 5.4  Flu (tumor) 1.5 ± 0.2 1.1 ± 0.20.6 ± 0.2  0.5 ± 0.05 2.8 ± 0.6 0.1 ± 0.1 0.1 ± 0.2  0.1 ± 0.04 ^(a)4H;^(b)2H; NC - not collected

TABLE 8 21-24 Hour Biodistribution (% injected dose/g) of At-211 LabeledPSMA inhibitors in 6-8 week old athymic mice (25 g) bearing both PSMA+PC3-PIP and PSMA− PC3-flu flank xenografts with and without coldblocking agent. Agent YC-I- YC-IV- PSMA- PSMA- [Lu]VK- [Lu]VK- [Lu]VK-27^(a) 11^(a) 620^(a) 904^(a) HS-549^(a) 02-90^(b) 02-90^(b) + 02-90^(b)(no (no (no (no (no (no (0.25 nmole (0.5 nmole Organ blocker) blocker)blocker) blocker) blocker) blocker) YC-I-27) YC-I-27) blood  0.5 ± 0.050.3 ± 0.1 0.1 ± 0.1 0.5 ± 0.1 0.9 ± 0.2 0 0.3 ± 1.0 0.03 ± 0.3  stomach9.4 ± 3.0 4.3 ± 1.2 1.9 ± 1.0 9.4 ± 2.2 12.6 ± 6.2  0 0.3 ± 0.4 0.4 ±0.7 spleen 8.0 ± 2.0 4.2 ± 0.8 0.9 ± 0.4 2.1 ± 0.7 2.3 ± 0.7 0 0 2.5 ±4.3 thyroid 6.5 ± 2.0 2.2 ± 1.0 0.9 ± 0.1 3.7 ± 1.4 3.8 ± 0.6 NC NC NCsalivary NC NC NC NC NC 0 0 0 gland lacrimal NC NC NC NC NC 0 0 0 glandkidney 57.4 ± 7.4  5.4 ± 15  7.5 ± 1.8 4.4 ± 3.5 2.6 ± 0.8 0.02 ± 0.20.3 ± 0.4 0.4 ± 0.5 PIP (tumor) 31.1 ± 9.8  12.3 ± 3.0  13.6 ± 3.3  12.1± 5.0  10.6 ± 9.9  9.5 ± 1.0 15.3 ± 8.0  17.5 ± 7.9  Flu (tumor) 1.2 ±0.2 0.6 ± 0.2 0.2 ± 0.1 0.8 ± 0.2 1.1 ± 0.3 0 0.04 ± 0.2  0.2 ± 0.3^(a)21H; ^(b)24H; NC - not collected

TABLE 9 Biodistribution Data for [¹²⁵I]VK-03-03 and [¹²⁵I]VK-03-03-Lu inMice.

1H 4H 24H 1H 4H 24H blood  1.6 ± 0.26 0.49 ± 0.08 0.09 ± 0.02 2.4 ± 0.40.46 ± 0.15 0.09 ± 0.03 heart 1.6 ± 0.5  0.9 ± 0.03 0.17 ± 0.08 1.8 ±0.4 0.57 ± 0.27 0.09 ± 0.04 lung 4.5 ± 0.6 2.3 ± 0.3 0.58 ± 0.2  4.8 ±0.7 1.56 ± 0.5  0.15 ± 0.05 liver  0.9 ± 0.15 0.4 ± 0.2 0.09 ± 0.02 0.9± 0.1 0.23 ± 0.05 0.06 ± 0.02 spleen 70.0 ± 20.4 37.4 ± 8.9  4.9 ± 2.746.6 ± 17.2 15.7 ± 7.0  1.2 ± 0.4 pancreas  1.8 ± 0.27  1.5 ± 0.05 0.26± 0.07  1.4 ± 0.19 0.82 ± 0.73 0.04 ± 0.02 stomach  1.0 ± 0.12 0.95 ±0.7  0.18 ± 0.06  0.9 ± 0.35 0.41 ± 0.18 0.07 ± 0.02 small 0.76 ± 0.130.37 ± 0.08 0.08 ± 0.03 0.76 ± 0.2   0.2 ± 0.05 0.03 ± 0.02 intestinelarge  1.2 ± 0.06 0.58 ± 0.19 0.11 ± 0.06 1.0 ± 0.2 0.26 ± 0.11  0.04 ±0.005 intestine fat 3.2 ± 0.7 4.1 ± 1.5 0.37 ± 0.28 3.45 ± 1.6  1.5 ±0.9 0.62 ± 0.8  muscle 1.0 ± 0.2 0.64 ± 0.22  0.1 ± 0.05  1.0 ± 0.450.32 ± 0.18 0.03 ± 0.02 salivary  5.0 ± 0.86 3.5 ± 0.4  0.6 ± 0.16 4.1 ±1.1  1.4 ± 0.46 0.15 ± 0.06 gland lacrimal 25.4 ± 4.1  15.8 ± 4.9   2.6± 0.76 18.7 ± 3.5  5.5 ± 2.5 0.7 ± 0.3 gland kidney  132 ± 18.5  165 ±14.4  141 ± 18.3  145 ± 26.4 199 ± 34  50.4 ± 25.9 bladder 5.0 ± 2.9 2.4± 0.5  1.6 ± 0.75 3.1 ± 1.0 5.5 ± 6.0 2.8 ± 1.4 Flu 2.0 ± 0.7  1.2 ±0.28  0.2 ± 0.09 2.3 ± 0.9 0.75 ± 0.27 0.09 ± 0.02 (tumor) PiP 44.7 ±12.2 57.0 ± 15.9 54.1 ± 6.3  51.9 ± 15.0 60.1 ± 21.0 53.0 ± 8.0  (tumor)

Example 4 Synthesis of Non-radioactive VK03-03 and RadiohalogenationPrecursor VK03-01

Tri-tert-butyl2,2′,2″-(10-(2-((2-(3-(((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)-5-(tributylstannyl)benzamido)ethyl)amino)-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl)triacetate(VK02-134): A reaction mixture of commercial2-aminoethyl-mono-amide-DOTA-tris(t-Bu ester) DOTA-amine (0.051 g, 0.07mmol), bis(2,5-dioxopyrrolidin-1-yl) 5-(tributylstannyl)isophthalate(VK02-118) (0.048 g, 0.07 mmol) (G. Vaidyanathan et al. Biorg & Med.Chem. 20(24) 6929-6939, 2012) and Et3N (0.022 g, 0.22 mmol) were stirredin DMSO at RT for 2 h. The reaction mixture was concentrated andpurified by flash column chromatography eluting with 2% MeOH/CH₂Cl₂ toproduce 0.032 g (38%) of oily material. ¹H NMR (500 MHz, CDCl₃) δ ppm8.71 (s, 1H), 8.42 (s, 1H), 8.32 (s, 1H), 3.45 (s, 2H), 2.91 (bs, 4H),2.61 (s, 47H, peak merged with DMSO), 1.63 (m, 1H), 1.54-1.44 (m, 7H),1.33-1.23 (m, 12H), 1.11 (t, J=5.0 Hz, 6H), 0.87 (t, J=5.0 Hz, 9H). ESMSm/z: 1150.8 (M+H)⁺.(13S,17S)-8-(4-Bromobenzyl)-1,7,15-trioxo-1-(3-(tributylstannyl)-5-((2-(2-(4,7,10-tris(2-(tert-butoxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)ethyl)carbamoyl)phenyl)-2,8,14,16-tetraazanonadecane-13,17,19-tricarboxylicacid (VK03-01): A reaction mixture of VK02-134 (0.270 g, 0.23 mmol),VK02-135 (0.138 g, 0.23 mmol) and Et₃N (0.071 g, 0.70 mmol) were stirredin DMSO at RT for 2 h. The reaction mixture was concentrated andpurified by C-18 column chromatography eluting with 70-100%acetonitrile/water, lyophilized to provide 0.095 g (25%) of white solidproduct. ¹H NMR (500 MHz, CDCl₃) δ ppm 8.69-8.55 (m, 3H), 8.31 (s, 1H),8.00-7.94 (m, 2H), 7.60-7.56 (m, 1H), 7.50-7.48 (m, 1H), 7.41 (bs, 2H),7.17-7.14 (m, 1H), 6.36-6.29 (m, 1H), 4.46 (s, 1H), 4.19 (bs, 2H), 4.10(m, 2H), 3.11 (m, 6H), 2.94 (m, 5H), 2.41 (m, 1H), 2.27 (m, 2H), 1.93(m, 1H), 1.61-1.55 (m, 10H), 1.49 (s, 16H), 1.41 (s, 28H), 1.33-1.28 (m,11H), 1.14 (t, J=5.0 Hz, 8H), 0.87 (t, J=5.0 Hz, 9H). ESMS m/z: 809.9(M/2+H)⁺.(13S,17S)-8-(4-Bromobenzyl)-1-(3-iodo-5-((2-(2-(4,7,10-tris(2-(tert-butoxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)ethyl)carbamoyl)phenyl)-1,7,15-trioxo-2,8,14,16-tetraazanonadecane-13,17,19-tricarboxylicacid (VK03-02): Iodine (0.012 g) was added to a solution of VK03-01(0.050 g, 0.031 mmol) in CH₂Cl₂ (2 mL) and stirred for 2h at RT. Thereaction mixture was concentrated and purified by C-18 columnchromatography eluting with 40-60% acetonitrile/water. The brown productwas used as such for next step. ESMS m/z: 1457.8 (M−H)⁺.(13S,17S)-8-(4-Bromobenzyl)-1-(3-iodo-5-((2-(2-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)ethyl)carbamoyl)phenyl)-1,7,15-trioxo-2,8,14,16-tetraazanonadecane-13,17,19-tricarboxylicacid (VK03-03): A chilled solution of 50% TFA/CH₂Cl₂ (2 mL) was added toVK03-02 (0.066 g, 0.04 mmol) and stirred at RT for 2 h. The reactionmixture was concentrated and purified by HPLC using C-18 column. ¹H NMR(500 MHz, CD₃CN+D₂O) δ ppm 8.24-8.22 (m, 1H), 8.13-8.11 (m, 1H), 7.89(m, 1H), 7.53 (m, 1H), 7.46-7.40 (m, 2H), 7.08-7.05 (m, 2H), 4.48 (s,1H), 4.43 (s, 1H), 4.16-4.13 (m, 2H), 3.64 (bs, 7H), 3.44 (s, 3H), 3.31(m, 4H), 3.24-3.14 (m, 10H), 2.41 (m, 1H), 2.34-2.29 (m, 3H), 1.83-1.79(m, 2H), 1.67-1.42 (m, 9H), 1.38-1.36 (m, 5H), 1.23 (m, 4H). ESMS m/z:1291.8 (M+H)⁺.

Example 5 Radiochemistry

Multi-Step Synthesis with Isolation and Purification at Each Step.

Synthesis of [¹²⁵I]VK03-03.

200 μg of VK03-01 was dissolved in 100 μL methanol in a borosilicatescrew capped vial. To this is added 2 μL glacial acetic acid and 7.0 mCiof a solution of Na¹²⁵I (Perkin Elmer), followed by 25 μL of a solutionconsisting of 1 mg N-chlorosuccinimide dissolved in 1 mL methanol. Vialwas capped, shaken, and allowed to stand 20 min at room temperature. Thereaction was concentrated to almost dryness under a stream of nitrogenwith gentle heating. To this was added 200 μL concentrated formic acidand the vial was heated at 60° C. for 60 min, cooled, diluted to 1 mLwith water, and purified by radio-HPLC (250×10 mm, 10 micron, PhenomenexLuna C18 column. Water/acetonitrile (both containing 0.1% TFA) Gradientelution. 15% acetonitrile to 50% acetonitrile over 30 min, flow 4 mL/m.[¹²⁵I]VK03-03 (1.0 mCi) eluted A 21.5 min. [¹²⁵I]VK03-03 in the HPLCmobile phase was diluted to 20 mL with water and loaded onto a WatersOasis HLB Sep-Pak, washed with 5 mL water, blown dry was a stream ofnitrogen and eluted with 2 mL ethanol. This was concentrated under astream of nitrogen.

Synthesis of [¹²⁵]VK03-03-Lu

The ethanol solution of [¹²⁵I]VK03-03 (690 uCi) was concentrated toalmost dryness under a stream of nitrogen. To this is added 150 μL 0.1MNaOAc (pH 4.5), and 25 μL 5 mM Lu(NO₃)₃ in 0.1M HCl and mixed bymicropipette. This solution was heated at 60° C. for 20 min, quenchedwith 100 μL 5 mM EDTA, diluted with 600 μL water and purified byradio-HPLC (250×10 mm, 10 micron, Phenomenex Luna C18 column.Water/acetonitrile (both containing 0.1% TFA) Gradient elution. 15%acetonitrile to 50% acetonitrile over 30 min, flow 4 mL/m.[¹²⁵I]VK03-03-Lu (270 μC₁) eluted at 22.5 min. Under these conditions,[¹²⁵I]VK03-03 eluted at 21.5 min. Specific Activity of [¹²⁵I]VK03-03-Luwas estimated to be 645 Ci/mmole based on the standard curve for[¹²⁵I]VK03-03. [¹²⁵I]VK03-03-Lu in the HPLC mobile phase was diluted to20 mL with water and loaded onto a Waters Oasis HLB Sep-Pak, washed with5 mL water, blown dry with a stream of nitrogen and eluted with 2 mLethanol. This was concentrated under a stream of nitrogen.

Example 6 Results

Radiolabeled small-molecule PSMA inhibitors are currently under clinicalinvestigation as imaging and radiotherapeutic agents for prostate cancer(PC). Astatine-211 is a 7.2 h radiohalogen emitting short range, highlinear energy transfer alpha particles well suited for treatment of PCmicrometastases. ²¹¹At labeled PSMA binding agents known in the artsuffered from high renal retention, resulting in radiation nephropathy,and deastatination in vivo. The presently disclosed subject matterprovides strategies for addressing those problems using a DOTAcontaining ²¹¹At- or ¹²⁵I-labeled PSMA agent, its nonradioactive Lucomplex, and co-injection of a well-characterized competing PSMA ligand,DCIBzL (YC-I-27).

Radiosyntheses were done using a one-pot multistep reaction sequenceconsisting of a) radiohalogenation of 1 with ¹²⁵I⁻ or ²¹¹At in methanolcontaining N-chlorosuccinimide and acetic acid, b) concentration, c)acid hydrolysis to give [¹²⁵I/²¹¹At]2, and d) metal complexation withnon-radioactive Lu to give [¹²⁵I/²¹¹At]3. Final compounds were purifiedby HPLC. Biodistribution was performed after i.v. bolus of 37 kBq (1μCi) into athymic mice bearing both PSMA+PC3-PIP and PSMA-PC3-flu flankxenografts with and without co-injection of 0.5 nmol DCIBzL (YC-I-27).Organs were harvested 1, 4, and 24 h post-injection (n=5 per timepoint).

Radiochemical yields (non-decay corrected) were 53-60% for [¹²⁵I]3 and12-26% for [²¹¹At]3. All agents had high uptake in PIP tumors (10-50%ID/g) with minimal uptake in flu tumors. Lutetium complexation ([¹²⁵I]3compared to [¹²⁵I]2) reduced retention of radioactivity in potentiallyproblematic tissues: a) kidneys (K) (4 h; 162±36 vs 18.2±4.9% ID/g; 24h, 30.6±14.0 vs 3.3±1.1% ID/g); b) salivary glands (SG) at 1 h (5.1±3.4vs 1.0±0.3% ID/g); and c) lacrimal glands (LG) at 1h (17.4±6.0 vs4.1±1.3% ID/g). Co-injection of DCIBzL with [¹²⁵I]3 or [²¹¹At]3 furtherreduced retention in K, SG, and LG: [¹²⁵I]3 @1 h, K 4.2±1.3, SG 3.2±0.7,LG 0.5±0.1% ID/g; [²¹¹At]3 @ 1 h, K 2.2±0.6, SG 0.4±0.15% ID/g, LG belowdetection, resulting in T/K ratios of 11, 27, and 44 @ 1, 4, and 24 h;and T/SG ratio of 64 @ 1 h for [²¹¹At]3. Stomach uptake of [¹²⁵I]3 and[²¹¹At]3 was low and comparable ([¹²⁵I]3, 1.8±0.2, 0.8±0.5, and0.1±0.04% ID/g; [²¹¹At]3, 0.4±0.2, 0.4±0.05, 0.4±0.7% ID/g @ 1, 4, and24 h, respectively, suggesting negligible deastatination occurred invivo.

By combining a lutetium loaded radiohalogenated agent with anappropriate competitive PSMA ligand, ([²¹¹At]3 and DCIBzL), it waspossible to obtain high (25.4±4.4% ID/g) and prolonged ²¹¹At uptake inPSMA+ PC3-PIP xenografts with low levels of activity in normal tissuesincluding kidneys, salivary glands, and lacrimal glands, with noevidence of deastatination in vivo. These results represent aconsiderable improvement compared with previously described²¹¹At-labeled PSMA inhibitors and further evaluation of the therapeuticpotential of this promising combination strategy is warranted.

Example 7 PSMA-Targeted Alpha Therapeutic Agent with Fast KidneyClearance

7.1 Overview. [²¹¹At]DCIBzL exhibited high efficacy as a PSMA-targetedradiopharmaceutical therapy (RPT) agent in preclinical models of humanprostate cancer (PC), but it caused renal failure due to its high uptakeand long retention in kidney. See Kiess et al., 2016. To enhance thetherapeutic index of the ²¹¹At-based PSMA-targeted agents,[²¹¹At]VK-02-90-Lu was developed and previously shown to have rapidrenal clearance while exhibiting persistent retention in PSMA+tumors.Mease et al., 2018. This example demonstrates the efficacy and toxicityof [²¹¹At]VK-02-90-Lu in experimental models of PC and in healthyimmunocompetent mice, respectively.

7.2 Methods. Two murine models of human PC were generated, asubcutaneous (SC) model of PSMA+PC3-PIP and PSMA-PC3-flu cells and ametastatic model of PSMA+ PC3ML/PSMA/fLuc in NOD/SCID/IL-2rγ_(−/−) (NSG)mice. Single intravenous injection of different doses (FIG. 3) was givento each animal and the tumor progression was monitored by measuring theSC tumor volume or by performing bioluminescence imaging for themetastatic model. CD-1 mice were injected with individual doses of 1.48MBq (40 μCi), 0.74 MBq (20 μCi), and 0.244 MBq (6.6 μCi), and theanimals were monitored for long-term toxicity.

7.3 Results. [²¹¹At]VK-02-90-Lu showed a favorable SC tumor-specificuptake as the ratios of tumor/kidney, tumor/salivary gland, andtumor/lacrimal gland at 4 h post injection were 2.9, 14.8, and 62.1,respectively. These ratios further improved at 24 h to 14.1, 85.7, and360.0. A dose-dependent response was observed in the PSMA+ PC3-PIP SCmodel, whereas there was no effect on the PSMA− PC3-flu model (FIG. 3A).There was also a dose-dependent therapeutic effect of [²¹¹At]VK-02-90-Lualso was observed in the metastatic model (FIG. 3B). Lower doses wererequired for the SC model due to higher levels of PSMA within the cellsthan in the metastatic model. No CD-1 animals showed treatment-relatedtoxicity up to 4 months after treatment measured by overall healthstatus and urinalysis

7.4 Summary. [²¹¹At]K-02-90-Lu is a promising candidate PSMA-targetedRPT with a favorable therapeutic index.

REFERENCES

All publications, patent applications, patents, and other referencesmentioned in the specification are indicative of the level of thoseskilled in the art to which the presently disclosed subject matterpertains. All publications, patent applications, patents, and otherreferences are herein incorporated by reference to the same extent as ifeach individual publication, patent application, patent, and otherreference was specifically and individually indicated to be incorporatedby reference. It will be understood that, although a number of patentapplications, patents, and other references are referred to herein, suchreference does not constitute an admission that any of these documentsforms part of the common general knowledge in the art. In case of aconflict between the specification and any of the incorporatedreferences, the specification (including any amendments thereof, whichmay be based on an incorporated reference), shall control. Standardart-accepted meanings of terms are used herein unless indicatedotherwise. Standard abbreviations for various terms are used herein.

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Although the foregoing subject matter has been described in some detailby way of illustration and example for purposes of clarity ofunderstanding, it will be understood by those skilled in the art thatcertain changes and modifications can be practiced within the scope ofthe appended claims.

That which is claimed:
 1. A compound of formula (I):

wherein: Z is tetrazole or CO₂Q; Q is H or a protecting group; m is aninteger selected from the group consisting of 1, 2, 3, 4, and 5; R isindependently H or —CH₂—R¹; wherein R¹ is:

wherein X₁ is —CR³, —C—X, or N, wherein R³ is H or C₁-C₄ alkyl; whereinX is selected from the group consisting of a radioisotope of iodine, aradioisotope of bromine, and a radioisotope of astatine; or X is halogenwhen at least one L is a substituted arylene; L is a linker selectedfrom the group consisting of C₁, C₂, C₃, C₄, C₅, and C₆ alkylene, C₃,C₄, C₅, and C₆ cycloalkylene, and arylene, each of which can besubstituted to unsubstituted; W is selected from the group consisting of—NR²—(C═O)—, —NR²—(C═S)—, —(C═O)—NR²—, and —(C═S)—NR²—; wherein eachoccurrence of L and W can be the same or different; R² is H or C₁-C₄alkyl; n is an integer selected from the group consisting of 1, 2, and3; Ch is a chelating agent that can comprise a metal; andpharmaceutically acceptable salts thereof
 2. The compound of claim 1,wherein R¹ is selected from the group consisting of:


3. The compound of claim 1, wherein X is selected from the groupconsisting of ¹²⁵I, ¹²⁴I, ¹²³I, ¹³¹I, ²¹¹At, ⁷⁷Br, and ^(80m)Br.
 4. Thecompound of claim 1, wherein at least one L is substituted arylene and Xis halogen.
 5. The compound of claim 1, wherein the chelating agent isselected from the group consisting of:


6. The compound of claim 1, wherein the metal chelating agent comprisesa metal selected from the group consisting of: Y, Lu, Tc, Zr, In, Sm,Re, Cu, Pb, Ac, Bi, Al, Ga, Re, Ho and Sc, and radioisotopes thereof. 7.The compound of claim 6, wherein the metal is ¹⁷⁵Lu.
 8. The compound ofclaim 1, wherein the compound of formula (I) is selected from the groupconsisting of:


9. The compound of claim 8, wherein X is ¹²⁵I or ²¹¹At.
 10. The compoundof claim 1, wherein the compound of formula (I) has the followingformula:

wherein L is selected from C₁, C₂, C₃, C₄, C₅, and C₆ alkylene; whereinX₁ is —CR³, —C—X, or N, wherein R³ is H or C₁-C₄ alkyl; and wherein X isselected from the group consisting of a radioisotope of iodine, aradioisotope of bromine, and a radioisotope of astatine.
 11. Thecompound of claim 10, wherein the compound of formula (I) is:

wherein X is ¹²⁵I or ²¹¹At.
 12. The compound of claim 1, wherein thecompound of formula (I) has the following formula:

wherein: p is an integer selected from the group consisting of 1, 2, 3,4, 5, and 6; and X is halogen; X₁ is —CR³, —C—X, or N, wherein R³ is Hor C₁-C₄ alkyl; and X₂ is selected from the group consisting of aradioisotope of iodine, a radioisotope of bromine, and a radioisotope ofastatine; and wherein M⁺ is a metal, which can be present or absent. 13.The compound of claim 12, wherein M⁺ is a metal selected from the groupconsisting of: Y, Lu, Tc, Zr, In, Sm, Re, Cu, Pb, Ac, Bi, Al, Ga, Re, Hoand Sc, and radioisotopes thereof.
 14. The compound of claim 12, whereinthe compound of formula (I) is selected from the group consisting of:


15. A method for treating one or more PSMA expressing tumors or cells,the method comprising contacting the one or more PSMA expressing tumorsor cells with an effective amount of a compound of any of claims 1-14.16. The method of claim 15, wherein the one or more PSMA-expressingtumor or cells is selected from the group consisting of: a prostatetumor or cell, a metastasized prostate tumor or cell, a lung tumor orcell, a renal tumor or cell, a glioblastoma, a pancreatic tumor or cell,a bladder tumor or cell, a sarcoma, a melanoma, a breast tumor or cell,a colon tumor or cell, a germ cell, a pheochromocytoma, an esophagealtumor or cell, a stomach tumor or cell, and combinations thereof. 17.The method of claim 15, wherein the one or more PSMA-expressing tumor orcells is a prostate tumor or cell.
 18. The method of claim 15, whereinthe one or more PSMA-expressing tumor or cells is in vitro, in vivo, orex vivo.
 19. The method of claim 15, wherein the one or morePSMA-expressing tumor or cells is present in a subject.
 20. The methodof claim 19, wherein the subject is human.
 21. The method of claim 15,wherein the method results in inhibition of tumor growth.
 22. The methodof claim 15, further comprising administering a blocking agent incombination with the compound of formula (I), wherein the blocking agentreduces accumulation of the compound of formula (I) in one or more PSMAexpressing cells in an off-target organ.
 23. The method of claim 22,wherein the off-target organ is selected from the group consisting ofblood, stomach, spleen, thyroid gland, salivary gland, lacrimal gland,and kidney.
 24. The method of claim 23, wherein the off-target organ isthe kidney or salivary gland.
 25. The method of claim 22, wherein theblocking agent comprises a PSMA-based blocking agent.
 26. The method ofclaim 25, wherein the PSMA-based blocking agent is a compound of formula(I) that is not radiohalogenated, wherein the compound of formula (I)used as a blocking agent and the compound of formula (I) used as atherapeutic agent can be the same or different.
 27. The method of claim25, wherein the PSMA-based blocking agent is:

wherein X is halogen.
 28. A one-pot, multi-step synthesis method forpreparing a radiotherapeutic compound of formula (Ia):

wherein X is a radiohalide, the method comprising: (a) providing aprecursor compound of formula (Ia′):

(b) contacting the precursor compound of formula (Ia′) with solutioncomprising a radiohalide and N-chlorosuccinimide, followed by theaddition of glacial acetic acid to form a radiohalogenated precursorcompound of formula (Ia″):

(c) contacting the radiohalogenated precursor compound of formula (Ia″)with trifluoroacetic acid to form a radiohalogenated compound of formula(Ia′″):

(d) contacting the radiohalogenated compound of formula (Ia′″) withNaOAc and Lu(NO₃)₃ to form a radiotherapeutic compound of formula (Ia).29. The one-pot, multi-step synthesis method of claim 28, furthercomprising quenching step (d) with ethylenediaminetetraacetic acid(EDTA).
 30. The one-pot, multi-step synthesis method of claim 28,further comprising purifying the radiotherapeutic compound of formula(Ia) by radio-high-performance liquid chromatography (HPLC).
 31. Theone-pot, multi-step synthesis method of claim 28, wherein theradiohalide is selected from the group consisting of ¹²⁵I, ¹²³I, ¹³¹I,¹²⁴I, ²¹¹At, ⁷⁷Br, and ^(80m)Br.
 32. The one-pot, multi-step synthesismethod of claim 31, wherein the radiohalide is iodine-125 (¹²⁵I) orastatine-211 (²¹¹At).
 33. A pharmaceutical composition comprising acompound of any of claims 1-14 and a pharmaceutically acceptablecarrier.
 34. A kit for treating one or more PSMA expressing tumors orcells, the kit comprising a compound of claims 1-14.
 35. The kit ofclaim 34, further comprising a blocking agent.
 36. A method for imagingone or more prostate-specific membrane antigen (PSMA) tumors or cells,the method comprising contacting the one or more tumors or cells with aneffective amount of a compound of formula (I) and making an image,wherein the imaging comprises positron emission tomography (PET):

wherein: Z is tetrazole or CO₂Q; Q is H or a protecting group; m is aninteger selected from the group consisting of 1, 2, 3, 4, and 5; R isindependently H or —CH₂—R¹; wherein R¹ is:

wherein X₁ is —CR³, —C—X, or N, wherein R³ is H or C₁-C₄ alkyl; whereinX is ¹²⁴I; L is a linker selected from the group consisting of C₁, C₂,C₃, C₄, C₅, and C₆ alkylene, C₃, C₄, C₅, and C₆ cycloalkylene, andarylene, each of which can be substituted to unsubstituted; W isselected from the group consisting of —NR²—(C═O)—, —NR²—(C═S)—,—(C═O)—NR²—, and —(C═S)—NR²—; wherein each occurrence of L and W can bethe same or different; R² is H or C₁-C₄ alkyl; n is an integer selectedfrom the group consisting of 1, 2, and 3; Ch is a chelating agent thatcan comprise a metal; and pharmaceutically acceptable salts thereof.